Visual Communication
in the Learning of Science
Final Report to ESRC
Background
The project arose out of Issues raised In our prewous ESRC project on explanation
(Ogbom et al 1996), and work by Kress and van Leeuwen (1996) on a grammar of
Images These prowded the major theoretical bases and the fundamental hypothesis,
namely that m Science Education Images were commg to serve various central
communlcatwe/mformatlonal
purposes, rather than more margmal ones such as
dlustratlon, enlwemng, memorabdlty/leamabdlty
An essentml assumption (as m Ogbom et al 1996) was that meamng M grounded m action,
mcludmg physical and commurucatlve action Only thus can meanmg escape the cmcle of
words dependmg on words We regard the meanmg of a scientific entity as ‘what It can
do, what It can have done to It, and what It is made of’
Objectives
1 To analyse and document the variety of roles of wsual commumc.tlon m school science
texts, and m wsual Images m use In science classrooms, and their influences on science
education, taking account of the context of the school wlthm the larger social context and
]ts mcreasmg orientation to wsual comm urucatlon
2 To prowde a typology of kinds and functions of wsual Images, m text books and m
classroom practice, based both on an analysls of the images and on empmcal mvestlgahon
of ways m which they are used and the meamngs pupils construct from them, taking
account of how these interact with pupds’ current conceptual understandings
3 To ]dent[fy rules which form the grammar of wsual Images used ]n science, so as to
describe theu pnnclpal resources for makmg and combmmg meamngs, by constructing
systemic grammars analogous to those which account for the workmg of verbal text
4 To mvestlgate methods of accessing knowledge and understanding m which wsual
Imagery plays an essential role, thus provldlng better means than currently exist for
assessing knowledge expressed wsually
ObJecfwe ( 1) The project has led to new and slgrnficant mslghts, as described m Results
ObJecfLve(2) The project has extended the typology prowded by Kress and van Leeuwen,
and has described key aspects of the uses of wsual commurucat]on m Science Classrooms
Objectwe (3) The project has made a begmnmg m ldentlfymg prudlces , It has slgmficant
things to say about Images as resources for makmg and combmmg meamng We have not
constructed ‘systemic grammars’, m part because the new wsual and verbal code IS m a
rapid stage of development, and m part due to doubts thrown up In the course of the
project whether th]s was m theoretical y possible or appropriate
ObJeclwe (4) The project has s~gruficant new understandmgs m thm respect In part there
M scope and need for further Investlgatlon, which might need a hlstoncal/comparative
component
1
Methods
Data were collected by surveying text books as sources, from videos of Science lessons,
with transcripts of verbal and as far as possible wsmd aspects (These transcripts were
used as materials m themselves, and as structural ‘sprees’ for descnb[ng associated VIsual
commumcatlon)
Interw ews were conducted with groups of school-chddren from the
classes m wh]ch wdeo-recordings
were made
The project also collected materials
produced by clukfren, both as ‘homework’, and as a set of posters produced In the context
of one set of lessons
The methods of analysls were based on those of discourse analysls, and of a wsual
semlotlc analysis, set m an mterdmclphnary framework of Science Ed ucatlon and Soc]al
Semiotics The primary concern was to find good ways of conceptuahs]ng semlosis using
Images m science, as opposed to documenting the frequency of various kinds of semlotlc
actlwty
Results
In the nature of the project, this ISthe largest section of the Report The discussion which
follows Mexemplified by Images from our corpus, collected m tbe Appendix
1. Analysm
of Images:
a semiotic
starting
point
The project began with a survey of Images In text books, and an mltlal description and
classlflcat]on of images there Tbe theoretical/descriptive
tool of the Kress and van
Leeuwen (1996) framework (K/vL from now on) prowded a useful nntlal starting point
This gave nse to a large Inventory of Image types, wh]ch broadly speaking, could be
accommodated m the K/vL theoretical scheme from narralwe vnuges such as the depict] on
of oxy-acetylene being used to cut through steel (Fig 1), to A.@icatmy
mzaga as In the
arrangements of geological formations (Fig 2), to tbe analytlc tmage$ of the human
digestive system (Fig 3)
The wide vanabdlty tv~thm these types of Images - old photographs, drawings, pamtlngs,
diagrams, flow-charts, cartoon drawings, comic-stnps - seemed tO require explanation In
pedagogical terms An old photograph of a World war One Zeppehn (Fig 4 What a Gas)
rmght evoke’ interest’ (see SectIon 2) A sequence of Images movmg from (semi-reahst)
photograph to drawing to (hlghl y abstract) diagram might have the dldactlc purpose of
makmg a particular element m the cumculum accessible (Fig 5 Magnet]c Fields)
The mvestigatlon extended the K/vL framework m several respects, particularly In
wlderung attention from single relatively context-less Images to larger umts cons@mg of
several Images, to Image-text relatlons (see SectIon 6), and from concern with the static
Image to the Image-m-use We also draw attenhon to another phenomenon - single Images
which combme several K/vL elements, e g narrative with classification
Here we briefly prewew these points, developed further later Pages of contemporaw
sc]ence text books generally consist of a layout of several Images together (Figs 2,3,4)
These layouts can foreshadow sallent aspects of the topic to come (Fig 6 The
Watercycle), deal with movmg from the general to the speclflc (Fig 7 Electromcs) or go
from the macroscopic to the microscopic (Fig 3), show bow essential characteristics
combine and relate to potent]al use (Fig 8 House L1ghtmg, F1g 9 More properties), relate
the everyday and ‘real’ to the sclent]tic and general/abstract, or wee-versa (Figs 7,8) In
such arrangements the various plctonal elements are always intended to be read as a
complex whole, as a wsuid [ext (see SectIon 6)
2
A crucial Issue IS the specmhzu~wmr of modes of cmrmumtcac~on (see SectIon 9)
Information of different kinds can be distributed across modes In different ways (see
SectIons 3,4,6,10) Thm suggests re-conceptuahzmg science-’content’ (Section 8) Sunk
Issues arise from mvestlgahon with falk andvnage m the class room (Sect]ons 5,9)
An instance of the combination of semlotlc features M Flg 10 Food Chain This combmes
narrative elements of the flow through vectors (arrows) of pesticides up the food chain,
and estabhshes at the same time a strong top-down h]erarchy of orgarnsms from predator
to prey The Image IS strongly layered, repetition of forms ]n layers suggesting c Lmses of
orgarusms at each level The Image can be thought of as a classlflcatlon wlthm a narrative
what these creatures do to one another, and how those actions orgamse them ]n relatlon to
one another
Another kmd of combination IS the classdicatlon of analytical tmages
L1ghtmg, we get analytical tmages (cmcmts) arranged In a Ieft-to-right
sen es and parallel The vertical relatlon m that between forrnabsatlon
above we get how the Images are represented m clrcmt diagrams - bel ow
might look on the bench
In F1g 8, House
classification of
and appearance,
w e get how they
The simple fact of arranging multlple Images on a page urges the reader to read mto the
arrangement possible relatlons between them
2. Functions
of Images:
a science
education
starting
point
Images m school science texts serve dmtmct functions, amongst which are
.
.
.
.
.
to attract attenhon, engage interest, motivate
to orient, to Indicate what Mto come - Image as (macro) textual orgamzer
to be knowledge - (See Section 8)
to be worked on - (See SectIon 4)
to show a procedure, commumcatmg how to do somethmg (e g hght a Bunsen
burner)
● to dlasrrate a written text about sn Idea or argument
. to prowde context, glvmg value or Importance to written text or other Images - (See
SectIons 3,4,6)
[n general such functions can be dmtlrrgulsbed by the dtfferent answers one gets to three
questions about an Image
what ISthe relatlon between this Image and the locally surroundlrrg written text and
Images?
. what Mthe relatlon of this Image to expected pupal actl wty at that pomt~
● what IStbe relation of this Image to the sc]entdi c knowledge m play at that moment?
●
These questions prowde a framework wlthln which we can discuss relahons between
Issues m the sem]otlcs of visual commumcatlon and the msues revolved m teaching
science
3 Image
under
construction
Some images m textbooks are there to be learned (Figs 5, 12, See SectIon 8) In the
classroom such Images are not presented to students fully formed, generally, teachers budd
up towards them, so that the final Image emerges httle by httle In this budd-up modes of
commumcahon other than visual Images are often cr-uclal, mcludmg talk and gesture
3
One teacher devoted a whole lesson to working towards Flg 12 (Day and Night)
In
retrospect It can be seen that the nature of the final Image Impbcltly gtuded everything he
dld (See Section 9) Movlrrg from written queshons to demonstrations
to a wdeo
sequence, he stopped tbe wdeo m freeze-frame at a point close to that of part of Flg 12
Gesture took over, hand movements converting the wdeo Image mto a schematic diagram,
makmg a Z-shaped gesture (Fig 13) to Impose anslytscal structure on the Image
The Image was constructed through a whole sequence of achwtles, not all using Images
but all directed at the construction of meamng for the Image The essenhal semlotlc point
ISthat Images ]rr science have to be thought about dynamically An eldetlc memory of the
appearance Mnot enough, It M the construchon and Its mtlonale whtch reafly matters
If meamng is grounded ]n achon, might one expect science texts to be full of narrative
Images, such as Flg 4 m which he meamng of ‘gas’ 1s constructed through ways of
compressing gases? Actually, such narrative Images are rare More typical M Flg 10 (The
Food Chain) In which all but one actions of eating are not represented wsually, but are in
the written text The action which N represented visually - by arrows - M the ftow of
pest] c]des up the food chain The Image ]s wsuall y orgamsed so that tke two sets of actions
(eating and taking up peshclde) classlfy organisms mto a hierarchy, Itself strongly
represented w sually The mearung of the hierarchy ]s constructed from actl ons
Language, rather than Image, can often be the more apt mode for representing act]on A
clear case IS Flg 15 Key to orgarrtsms, m which the whole Image M a class] ficat]on, but
the basis of the classlflcatlon revolves actions expressed In words (e g “make seeds and
have roots”) Again, In Flg 16 Foldlng and Faulting, the Image shows the result of an
action, the written text expresses the action (“Forces
pushed on the layers”)
Static Images cannot show change except wa conventions such as the use of arrows
Therefore change and action are often shown either by an expllclt ‘before and after’ pair
(generally arranged left-right), or by a single image showlrrg somethlrrg ‘after’ a change,
posing the Issue of how that change might have come ahout Actson has to be readm
4. Image
as subject
of work
We treat reading as work Many Images exphcltly mwte ‘vlslble work’ Flg
proper-hes, asks us to read m a left-right dlrect]on to construct an ongm - purpose
Flg 11 Roadstones mwtes the reader to perform internally the action of scraping,
Oxygen shows a young woman heating a substance, wearing protecfwe goggles,
instructions to act m thm way
9 More
relahon,
Flg 19
as dl rect
Many Images mwte ‘Irrwslble work’ comparing and contrasting of classdicatory Images
(Fig 2), mfemng a prior action which led to a state of affa,rs (Fig 2), mowng between
speclf]c and general or emplncal and theorebcal F]g 17 instructs the viewer to estabhsh
relatlons between an electron microscope photograph of a cel 1,and two draw]ngs of a cell,
m a relatlon of ‘]maglne this as that’ Other forms of work revolve series of actions over
time, movmg from Image to written form, from image m one mode to Image m another
mode (Fig 16, photograph and drawing) A sequence of drawings as m Fig 20 More
cells, can show how to draw a cell, or develop conceptual understanding of what cells are
A pedagogic queshon 1s how much and what k]nd of work an Image demands, an
equwalent semlotsc question N about the mformahonal density of an Image, and about the
speclahzed pedagogic and cumcular functrons relative to each other of wntlng and Image,
or of talk and Image (See Sechons 6,8,9)
4
5. Students’
valuations
and
readings
of images
In mter-wews we asked students to respond to Images m texts used ]rr their classroom
They clear] y Idenhfied ‘sclentdic’ Images, and those wh]ch “are for learmng or studying”
We also mvestlgated how they read text book Images they had not seen before, getting
them to compare Images with slmdar sclent]tic content They showed dlstmct preferences,
and evidence of active reading of Images
Students’ readings reveal that Images are not considered as Isolated entitles but relate both
to other pieces of text on a page and, more generally, to other pieces of knowledge
There
are two mam dimensions along which students appear to operate one relates to percewmg
and estabh shmg relatsonshlps at both mtra- and inter-textual levels Students dmcem the
underlying textual conceptual coherence They readily integrate and relate to pictures they
have seen earher The second dlmenslon was their ablhty to project expenentml knowledge
onto the reading of the Image, both of everyday and classroom culture, reading Images
agalrrst a background of expectations
Knowledge about their local reahty M used to
interpret a picture showing sunshine m the Arctic Circle at mldrught (Fig 12) Classroom
culture helps them recogruse th]s particular Image as having the function of enhvenlng the
text, by contrast with a schematic diagram of the solar system which they treat as a piece of
knowledge ‘Sclenhfic’ Images ]dentlfied by pupds included hne drawings and diagrams
but excluded photographs and cartoons, those Iabelled ‘non-sclentlflc’ generally contain
humarused characters and have high colour saturahon - m K/vL these lack high scientific
modallty For students the meamrrg and slgmficance of Images are to be found m their
actual and theu potential use m Ieammg actl w ties
Imtlal comments (how “mce” they looked or whether one “hked” them or not, talk about
wsual compositions wh]ch please the eye and look attractive), suggest that the first
engagement wth Images happens through an atfective channel The aesthetics draws m the
use of colour, balance between amount of text and Image, these are referred to as features
wh]ch help catch the wewer’s attenhon Colour w seen as a key feature which allows an
Image to be ‘read’ and interpreted m a g]ven way, e g FIg 16
These mslghts led us to consider another source of data wsual materials which students
themselves produce The materials considered included posters wh]ch students were asked
to make around the topic of ‘particles’ The content of the posters derives from prewous
teaching, the content wfuch the students represent m their posters can be read as md]cat] ng
what they regarded as most sahent about the top]c Of course the genre of poster Itself IS
mfluentlal, nevertheless the range of matter represented vaned huge] y - from a focus on the
graphic aspects of the poster alone, to graphics deployed to best dmplay/arrange content, to
mnumal graph]c effort and a concerr@ation exclus]vel y cumcular content Flg 21 Posters
shows a few examples (the actual posters were A3 size)
6. Textual
relatlons
We have taken It throughout that Images m science texts are not mere ]Ilustratlve adjuncts
to a written text, but themselves commurucate essential Ideas, formmg text-hke objects,
and pa-oclpatmg In textual structures of various kinds We therefore extend the term text
to commurucatlon which happens through Images, or through Image and wntmg (and
speech or gesture) This makes a problem there M no word for the code using Image +
language There are names for many types of verbal text, genre-labels such as reporf,
mlerwew, poem, conversutcon, lecture There are no such names, as yet, for the textobJects wluch we have investigated Some seem to be emergmg for Instance double-pagespread IS not a slgmticant umt of the h]gh era of wntmg, but seems to be becomurg a urut
m an era when visual-spahal entitles m wsual commmucatlon are becommg promurent
Larger-sized umts also seem to be evolving for instance urufs of work rather than
chapterh
5
We have looked at mtra-textuai relatlons in language there are dewces for estabhshmg
cohesion for instance the system of Iexlcal conjunctions - but, although, and, rherefore,
TOthar, so - for relatlons between clauses and between sentences, and that of@rortc@ anaphora, cataphora, exophora (generahsed delxls) - at a larger textual scale
Qu,te slmdar relat]ons - simple and, then, these (Figs 2, 14, 16) are present m v,sual
texts But we do not suppose that systems developed for language WIIIcarry over exactly
mto the vmual or wsual+verbal codes However, delxls IS cIearly ewdent, for instance m
“For each example above “
F] g 9 More Properhes “The rocks and mmerals -’,
In Flg 22 A switch m time we have “build the cwcuzl below “ acting both phoncally
and delctlcally In Flg 10 The food chain the Identical topology of layers mdlcates ‘the
same’ relatlon repeated
Textual structures are der]ved from the potentials of the wsual mode Flg 9 More
proper-hes, uses Ieft-nght orgamsahon for ‘lmtlal state - final state’, Flg 12 Day and mght
contains a wsual structure of deduction from theorehcal account to practical consequence
Indeed, If as we suppose, different semlotlc modes are used for speclahzed pu~oses (see
section 9), then we expect textual forms and relatlons which d]ffer from those of purely
verbal texts Common forms are ‘part of’ relahons (analytical Images) (Fig 3), luerarclues
(F]gs 10, 15) and classlficat,ons (Fig 2)
In sections 2 and 9, we suggest that dldactlcs and epistemology maybe related sources to
account more generally for charactermt] cs of textual structures An Image may have the
funct]on of ‘arousing interest’, because It M thought close to the eplstemologlcal posltlon
of students (Fig 4 Zeppehn) A umt on Astronomy we studied seems to be orgaruzed
slgmficantly by such conslderatlons, starting from an Image of Stonehenge makmg appeal
to the relatlon of ‘known’ to ‘unknown’, movmg as In Flg 12 to a visual/theoretical
account of the Earth m space, and from that to the photograph of Spltsbergen m June
Five pnnclples for anrdyz]ng the developing vmual + verbal code are worth considering
(1) How are Image and wntmg integrated? Do they alternate, are they simultaneously
presented (e g Figs 2, 3)?
(2) The frequency of each mode m either wntmg or Image constant or mterrmttent,
or Meither ‘punctuatlonal’ In relatlon to the other?
(3) Is there a clear mformat[onal hierarchy of modes? Are wntmg and the wsual
equal, or ISone dommant?
(4) In the page as a visual/spatial umt, and as a semlot]c resource, what are the
spatial posmomng of language and Image? (contrast Figs 3 and 10)
(5) What Mthe message funct]on m ]t dlustratlon (F,g 14) or elaboration (e g F]g
8 House-hghtmg where the verbal metaphor of ‘branches’ Mwsually elaborated), or
M It extension (Fig 5)
7. Representation
and
andlence
Sc[ence education IS m the midst of a transition from one form of
wntmg-based, to wntmg-plus-]mage as a new commurucatlonal code
explanabon What (changed) conceptions of the school population
characteristics of text books currently m use? What characteristics
addressed by the new text book?
text book - largely
This shift demands
are encoded m the
of the audience are
The audience of secondary schoohng has changed over the last 4-50 years science m
schools now addresses a mass-audience
Some changes are, we think, due to thls factor
There Ma close mterrelatlon between changing conceptions of who the students are, what
6
Ieammg 1s, how knowledge IS gamed or transmitted, what a cumculum subject can or
should be, and what Its purposes are The school-audience
]s not now soc]ally
homogeneous (with concerns about ethmc, class and gender-difference), m not 6hte, and
cannot simply be ‘given’ knowledge It has to be made ‘interested’ m the subject, and the
pages of texts speak of thm need to produce ‘interest’ (Figs 4,6,7) Talk of ‘S.clentdic
hteracy’ points to new purposes prowdmg access, as a pubhc good, to the mstltutlon of
sc]ence as a reqrnrernent of economic and pubhc hfe
8. Image
as knowledge
Exammahon questions m science can make the demand, “Draw a fully Iabelled diagram
of “ (e g a plant cell, an electric motor) Teachers normally set as,de time for such
Images to be copied mto exerc]se books Those who have learned sc]ence have m their
repertoire a set of such learned Images, more or less instantly recogrusable
and
reproducible They are a part of one’s scientific knowledge Thus - uncontroverslally - we
can point out the very substantial amount of sclentlf]c knowledge tamed pnmanly m
Images, e g the human dlgeshve system (Fig 23) Essentially the same figure can be
found m a wide variety of science texts, new or old
There ]s stall a wide-spread prejud]ce that ‘real knowledge’ M m words, not m images
Syllabuses rarely contain Images, a stereotypical philosophical wew of sclentlf]c
knowledge also sees It as made of laws and defuutlons - of verbal structures Our work
challenges this prejudice by demonstrating that m uch sclentdic knowledge M pnmanl y m
the form of Images, and that this is the case for the workmg sclentlst as much as for the
school pupl I These ‘Knowledge Images’ are such by being re-usable chunks of/bought,
avadable for use m thmkrng
An mterestmg class of knowledge-r mages are those which hold conceptual structures,
(e g Flg 6 The water cycle) It brings out the essential point that this M ev)dently just one
representation of the water cycle It contains much more ‘reabstlc’ detad than m usual, with
tension between the parhculanhes of the places represented and their genenc status, but ]t
emphasises the essential structure, namely a cycle of arrows represenhng flows The sea,
river, trees, clouds and ram are any sea, river, clouds and ram, the sewage works IS any
form of water collection and treatment, not the particular sewage works of this town
The wsual Importance of such Images JS sometimes much more general and conceptual
Figure 6 may develop from being ‘the water cycle’ to being ‘a cycle’, Figure 15 may turn
mto an example
m general of ‘a key’ These are at bottom wsual concepts Such
knowledge Images often get a verbal tag Feynman diagram, Ellmgham diagram, dipole
field, series clrcult
Of course knowledge Images do not stand alone Abstracted structural Images wdl often be
shown along with Images prowdlng a ‘reahty check’ (e g Figs 3, 16 17) Written text
may help transfomr the Image mto ‘sclentlfic narrat] ve’, mto a story about what does what
to account for what
Some sc]entdic knowledge M u-reduc]bly wsual Not to know what the DNA chain looks
hke M not to know about DNA, not to know the shape of magnetic fields IS not to know
magnetmm They are, set m them network of related representations, the actual content of
the knowledge to be learned
9. Localised
epistemology
- the
‘obvious’
In prewous work (Ogborn, et al, 19%) we put forward the view that explanation stops
when what has to be explasned has been made to seem ‘obwous’ m terms of the nature of
7
things as understood m that context
D] fferent modes of commumcahon
can make
different things seem ewdent to different groups or mdlwduals
Talk about summer and
winter WIII presume as ewdent that summer Is warm and winter M cold An vnage of the
whole earth with sunhght falhng on It wdl presume that the earth M round and that the sun
warms the earth where Its hght falls on It This leads us to expect that the ‘local
epistemology’ of a communl cation - what al fhat P@ It assumes. what It seeks to
understand, and what counts as grounds of knowledge, may vary as the mode of
commruucat]on vanes
In observations of science lessons m the project we could see such effects
Here m a
sketch of a pair of lessons on the Earth m space showing the ‘architecture’ of shifts m
Lesson 1
VERBAL (sfmken)
fMAGE
MODELLING
IMAGE
MODELLING
IMAGE.
VERBAL (written)
problematlzlng, queshomng
Christmas m Austraha” setting up an Issue to be d]scussed
enacting’ how things are’ with a material, physical model
ammated wdeo, a stall Image from wdeo used as diagram
enacting the dymumc wdeo with model
lnterpretmg a textbook-style Image
constructing note-book style explanations
Lesson 2
IMAGE
IMAGE to VERBAL
VERBALto IMAGE
MODEL to VERBAL
VERBAL (written)
reconstruction of an Image from the prewous lesson’s work
converting an Image mto a verbal classlticatlon of seasons
Interpreting verbal (written) texts and Images wa an Image
generating narratives from enacting the model
constructing written answers to hypothetical questions
Different modes of commurucatlon are hkel y to dispose learners to vary what they treat as
ewdent, and what is m need of being accounted for The mode used may depend on who
the explainer takes her or hls audience to be
Several semlotlc modes are used m the construction of the argument We show m detad
how m each the grounds of argument - the local epistemology, shifts m function of the
mode m use That which seems obwous changes from moment to moment
10. Representational
commitment
We owe to Keith Stenmrtg the fundamental mslght that all representation m Images
Involves speclflc commitments to ‘how things are’ It m possible to make an Image
showing X to the left of Y, or to the right of Y, but not dwr to the left of or to the right of
Y For Stenmng th]s was Important m grapblc support for arguing For us, It has a very
general Importance
Take Flg 20 (More cells), a diagrammatic representation of plant cells The representation
needs a cell wall, and mslde It a nucleus, chloroplasts, and a vacuole The last three must
be ms~de, but just where inside 1s not of Importance
But the nohon of ‘An object
somewhere’ IS not wsuafl y representable The most that can be done M to avoid placl ng
objects m posltlons which are special by vmtue of symmetry or topology, for example at
dead centre Why IS the cell of Flg 20 rectangular?
Flg 17, More plant cells, 1s a
representation of a plant cell from a different text The shape IS different but st]ll angular
The d]agram has to represent ‘some defimte shape or other’, but can only do so through
choosing a particular defimte shape a rectangle or a polygon The key feature m ewdently
the angulanty By contrast, m both texts, ammal cells are shown with mregular walls The
difference needing to be represented M that plant cells have thick and rather ngld walls
which gwe them a defuute shape, whdst many ammal cells have flexlble walls
8
Flg 24 Changing State, able to be read as a htchen scene m which a small child M m
danger from a large boding kettle, m m fact intended as a set of exampIes of processes of
change of state Such difficulties of mterpretmg representational commitments frequently
arise In Images to be worked on (See SectIon 4)
The notion of representahonal commitment helps to account for the high modal [ty (high
truth-value) gwen to flat hne diagrams m sclenhflc and techmcal contexts By avo]d] ng
cornrmtments to parhculanhes of place, obJect and hme, they are read as showing how
‘anythlrrg of this kind’ might be, and so are on offer as general rather than particular
truths The water cycle Image (Fig 6) fads to do tkus, no doubt m the interests of seemmg
very concrete But that concreteness ISbought at a price
11. Case
Stud]es
In addltlon to the above analybc framework, It M necessary to show m addlhon how, both
In text books and m classroom lessons, the elements discussed are articulated and
integrated To this end we have compded a number of case studies of complete texts and
series of lessons, showing how the meamrrg-makmg with Images 1s orchestrated
Activities
As enwsaged m the ongmal proposal, a conference was orgamzed for prachhoners of
various kinds teachers, pubhshers, designers, academics, pohcy-makers and researchers
A further semmar was held with the author and the editor of a successful series of science
texts Useful relatlons were estabhshed w]th tbe ESRC project “Multl-media corps-based
longitudinal study of chddren’s wntmg” at the Uruverslty of Lancaster, dmected by Dr Roz
Ivamc and Dr Tony McEnery
outputs
In addlhon to papers and semmars menhoned m our research report, the following
dmsemmahon achwhes are m tram, addressing tbe two main audiences, namely a science
education audience and the more general sermotlc and d]scourse rmalysls audience
A paper by Kress, Ogbom and Martins ‘A Satelhte wew of language some lessons
from the science classroom’ Mm press for the Journal Language Awareness
Kress M glwng an mwted paper to the Round Table on Social Theory and
Discourse Analysls, Cardlff June 1997, on our concept of ‘locahsed
epistemology’ and Its Imphcahons for dlscourae theory
Martins IS glvmg an mwted paper at the Conference of the European Science
Educahon Research Assoc]ahon (ESERA), Rome September 1997, on
students’ responses to wsual commumcahon
Ogbom IS gwmg an mwted paper at the Conference of the European Associahon
for Research m Leamrrg and Instruchon (EARLI) Athens August 1.997, on
wsual commumcahon m science
We are m discussion with pubhshers about a book on Visual Commumcahon In
Sc]ence, dlscussmg the work of the project and its relahon to current theones
of comrnumcahon
Several further papers are m preparahon, addressing both science education and
semiotic or discourse theory audiences
9
Impacts
Some of the findings of th[s proJect have been dscussed with the proJect at Lancaster, and
It m hkel y that they WI1lfind use there, m the descnptlon/anaIy sls of chddren’s wsual and
written textual development
One of the directors has been asked to give a Keynote
address to an audience of education researchers on findings (Umverslty of Southampton,
March 199S) Papers (see Report Form) wdl be given at several forthcoming conferences
Future Research
Priorities
In thm project we have continued a sh]ft, to be developed further m our forthcoming ESRC
project on Rhetorics of the Science CIassroom, from studies of chddren’s spontaneous
Ideas to studies of processes of teachrng UltI mately, the two need to be brought together
From a semlotlc perspective, the urgent need continues to be to broaden the concept of
commumcatlon towards a more multl-modal
one, which recogmses
botb the
dlstmctlveness and the mtegratlon In commurncatlve practices of different modes of
commumcatl on
Specifically, the present proJect places on the agenda of discussion of schoohng and of
pubhc understanding of science, the question of wsual commumcatlom as both cr-uclal to
science and as a soclo-culturat sl-uftof great long-term .sIgmticance
References
Kress G,van Leeuwen T(1996)Readmg Images Thegrumnrur ofvisuuldeslgn
London
Routledge
Ogborn J, Kress G, MartIns I, McGdllcuddy
K (1996) ExpkmungScterzce
mihe
Classroom Buckmgham Open UmversltyPress
10
Appendix
Figures
Flg
Flg
Flg
Flg
Flg
Flg
Fig.
Fig.
Flg
Flg
Flg
Flg
Fig
Flg
Flg
Flg
Flg
Flg
Flg
F]g
F]g
Flg
Flg
Flg
1
2
3
4.
5
6
7“
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
‘Oxy-ace@ene’
Reck I-hstory
The Gut
What a Gas
Magnehc Fields
lle Water Cycle
Electrorttcs
House L.@dog
More properhes
The Feed Chain
Roadstone.s
Day and N@rt
Zshaped gesture
What makes Gases usefirl
Key to Orgamsrns
Folding aod Fauhrng
More. plant cells
Waves
Oxygen
More Cells
Posters
A Switch m Tune
Dlgestmg Food
Changing State
~;7
—-—.
-.—.—
Oxygen
- —..
.-
--
——.—-.
--- ---. . .. —
m.
.
—=..
.
,
r,.x
1
.- . .
substances that burn m am WIJIburn faster ]n
oxygen Oxy-acetylene torches can cut metal very
fast the hot metal burns m the oxygen-r!ch gas You
can try burning some substances m
oxygen, but you must take care
Think safe all the time
A@
Burning
things
in oxygen
@
You must wear eye protection
You must
protect your table with heatproof mats
YOUcan bum some of these substances
– copper
won wool
sulphur (use only a rice-grain-sized
piece, beCa USe
the gas produced IS very poisonous)
a spill
magnesium (do not look directly at burmng
magnes]um, or It may bllnd you)
s Heat each of these substances m turn unhl It IS red
hot or catches f}re Then put It qmckly mto a
test-tube of oxygen The picture here should
help you to do this safely
A
. Write a reporl on what you see For each
substance, say what lt was ltke before, during
after heating
All the substances
Copper, magnes[um
and
that yOLIburnt produce malts
and Iron oxides are powders
The spdl and the suiphur make oxides as well, but
they are gases S1lIphur oxide IS a very pommous
gas
When the spill burns, lt makes hydrogen oxide
and carbon d]ox]cfe Llquld hydrogen oxide IS better
known as water
You can test for carbon dioxide gas by
shaking lt ln a tube with some hmewater
The
hmewater WIIIgo cloudy If carbon dlox]de IS
mixed w]th It
62
*
W!qg!$itzlhou$
.W
Rock history
%
How can these geological formations
e
2
be explamed~
What do they suggest about the history of the area?
o
What do you th]nk they wdl look hke m a mdhon years from now?
e
is
to
gs
a The8e Au8tr1an mountams are far from the
sea, yet them rocks conta]n fo8s11sof tmy
sea creatures
—,
{
b A lava tube m Hawau
c A 8ea stack m the Orkney Inland8
I
—-
e Part of the Grand Canyon m Arizona
65
‘—
..
..
—
. .. .. ——..
!=.(*
The gut
3
,#/-$rK
Many parts of the gut wall have special
cells wh]ch produce enzymes These
enzymes help to break down the
Iar<e food molecules mto smaller ones
— Mouth
Teeth break down large lumpsof
food mm smaller parc,des
Enzymesm sahvzbreak large
,mrch molecules mco smaller
sugar molecules
Glands m the
stomachImmg
These gweout
dtgesttve pees
I
I
I
The gut has two lobs
- breaking down food so that lt can be
absorbed mto the body,
- helping the food molecules into the
blood so that they can be carried
round the body
e
Both jobs are done as the food passes
along the gut
)’,
mlcrogmph of
I
UIIIIshowtng
the large
surface
/ ofl
,
I
area
The surface of the small mtestlne IS
covered w]th finger shapes called VIIII
The VI1lLgive the gut a very large
surface area This g]ves food molecules
more chance topass mto the blood
#fl
\
h
Large mtestme
Scanning
electron
J
D,gest,on complete water
.bsorbed m make wastes more
mhd
S,XW bacwr!a Ihwnghere make
,,c,mfim wh!ch can be absorbed
Rectum
W,SC,S stored wm they can be
passedout or che body
I
t!
1
The d!gestwe
$d’
Have you got the guts?
. YOUhave bee” given the job of explamlng
how the rut works for a TV science
program;e
You have a ten-mmute slot m the
programme wh]ch wdl be broadcast at 730 m
the evemng Many chddren and adults wdl be
syste
watching The producer wants you to include
at least one working model, an experiment
and a chart
. Yo” must also prepare a factsheet This WIII
be given free to anyone who writes In It
wdl be printed m two colours on both wales
of an A4 sheet of paper
119
~~
.-
What a gas!
Gases and their uses
Gases are all around you, even though you cannot
see them Here are some important gases
Hydrogen ISvery bght It explodes
used as a fuel m rockets
FL?
4
with alr and M
Ammoma M used to make ferhhsers, textdes and
exploswes
There would be much less food m the
world }fwe dld not have ammoma
Natural gas M made from animals that died and then
rotted mdhons of years ago It M trapped under the
rocks Because lt burns well, It makes a good fuel In
mmes lt M called flredamp because It can cause
explOslOns
Argon IS a gas that IS hard to change mto anyth]ng
else It M unreactive
Argon IS used to fdl hght bulbs
Because lt M so unreactive, lt stops t~ w]re fdament
m the bulb from burning out
Carbon dioxide M the fizz m flzzy drinks This gas M
also made when things burn Too much chrbon
dioxide stops a fire altogether
Plants turn’carbon
d!ox]de mto food called carbohydrate
,
●
●
Oxygen M the gas of bfe All ammals need oxygen to
stay alive It is also used to help things burn m
welding torches and m rocket engines
76
DISCUSSwith others In your group what the word
GAS means Write down how your group would
explain the word to someone at jumor schOOl
Make a hst of the gases that you know You can
start wmh the SIXon this page, but there are many
others If you can, say what each gas does, or
where It is found
4.14 Magnetic
‘9 5
fields
Plottinga field
\,
.
JI.
&
m’
\.
(!5
/
‘W&’
mDlomna
I
A’!
,.,
Put a magnet m the m]ddle of a p]ece of paper
Draw round It to mark ]ts posltlon
●
Place a plotting compass near one end of the
magnet Mark the position of the needle with
two pencd dots.
●
Move the compass so that the needle hnes up
with the last dot YOUmade Mark the poshon of
and so on untd you reach
the needle again
the magnet or the edge of the paper
●
Jom up the dots When you do this, you are
drawing a field hne
●
Repeat, starting at ddTerent points round the
magnet You can draw any number of field
hnes, but It’s simplest not too show too many
The compass
Field hnes around a bar magneti
/“”
●
Magnetic forces are acting m the space around the
magnet There is a magnetic field m this space
Magnetic fields can be studied using a small
compass Inside the compass IS a tmy magnet
called a needle It IS on a spindle and can turn
freely The north end of the needle IS a pointer
Near a magnet, the needle M turned by forces
between ts poles and the poles of the magnet The
needle comes to rest with the turmng forces
balanced
“
1
wilimmr~”
)
Iron tihngs, sprinkled on paper over a bar magnet
The fihngs have become tmy magnets –pulled mto
posltlon by forces from the poles of the magnet
comoass
Field lines between magnets
Poles dlflerenl
The field Ilnes run from norlh to south
neutral
poml
‘@9
● The Ihnes show (he dwecuon a compass
They run from the north ple
the south
c The Ileld IS Wongesl
needle would porn\
01 the magnet round 10
where Ihe Ihnes are cl-gelher
x
%% >
Poles (he ~ame
Al poml X !he held Irom one magnet cancels the held from the
other X IS called a neutral point II YOU Placed a compass al X
the needle wouldn’t be turned by the magnets
L-’ /
~g~
Electronics
Circuits
Transistors
In your f!rst clrcults you USCLItorch bulbs pmnecf
wtlh wires Modern electrical cqutp,nent USC, the
sa,ne bas,c ,deas f3ut !f YOU look tnmde a cmnputeI
there are “ot many wtres or torch bulbs The w,re~
and bulbs have been replaced by electronic dcv,’e.
I!ke traIwIstoIs, chips .ind Ilght-em, ttln$ dmdw
Tranststom and ch!ps are example. OISCI$II.
speLI.1
crywals I,kc
sd!con Tr.ns,stom work because they only COIMIUCI
electr, ctty m the right ccmdtt, o,w They arc useful
because they can turn on and off very fast, and they
need very I,ttle electr!clty
conductors They are made from
A trnn., stor w . spe., al WHIII .cmdu.
to,
[t lhcI\tl, tcc
connections a base, a collwto, a,!d an c,nfitteo
When a small cu, rent ,. p“l on the b,!.c, ,t MS a
tm. <h Inrge! cut, ent flow between the collccto, and
the e,nttter % a t,ny .unenl cm rent, ol a n,uch
large,one
●T,y th, s watt, detect”, c,,.,, (I
An electromc Ilght
Gy,Mcanmake elect,o,,,cctrcu,k
w,th
W(W5
lake
r-
the c!, cttits you ,nmde before The d! ffwulty IS that
the contacts are poor, and Sometl!neb III IIII:S do
not WO,k lt IS far bette, to soldcI the .o, npox>ts
T
I=J
‘!2
I(U,
(,
lm{t
Here ,s a ,Im Plc
cIrcu It to operate a
Itght-em, tt, ng
d!ode (LU7
,—---
[L
———.
_—
—..-.
..—
...
-
-. .. .. ..
-
((m,,
. .
Th!s design shows the mmc LIICUIt solderccl on
,natrtx boa, d TIM’ boa!d IS cheap .md can be Ieused
[
—-.
m
..&
—- —...
--—
1
<—-:------’~
BFYS , craou,c.r . ddcr
~-
~c. _——
140
..s
–J
,, h.
r,,h, “a” mud’
;:~
When the probes touch soII, eth, !Ig w.!, a .eIY
small cu!rentgocs from the battv!y tlII. w# the
wale, to the baw Or the t,.,,s,,m,
rl,, s CU,, mt IS
b,g e,,ough tO .,ake the t,a,,, t$to, wo, kt M the
LED I,ghts “p
House lighting
~~~ere are two important ways of connecting bulbs m a
, . C@cujt
##ne’
,~
) !;
● in parallel
fp%$y~ .;Thebulbs& all m
The bulbs are m
●
., Vdei@e’mw
“?<qx?%%
.
branches
:’
jL
=8=
jkd
,
$
i,’
~.-{
,,,
$
!!!
7;.
*
.4
‘
.,..
,.
c,
km
1.
..t
[“”
One of these ways of connecting
bulbs 1s used to solve
important design problems m your home
In your home you want
● bright
hghts
● hghts that stay on even when one bulb breaks or M
removed
>
-1
1 Build a series cmcmt and a parallel cn-cuit, using two
Parts needed to
budd cmcult
batteries m each
2 Fmd out which cmc~t would be better for house hghts
Write about your experiment(s)
i
Include
. Title
. Method
Details of what you&d
. Results
Deta.ds of what you found out
. Conclusion
Explain wluch circrut M better for house hghtmg
~,*fJ\
!#~. .~~
@,(
\\
82
I
\
k —-------- .
.Al!
Write a report of the mvestlgatlon for the cIv1l engineer
of budding the road
Describe the tests you dld
Recommend one of the rocks for the road’s surface
m charge
P
B
More
for fuel
coal
1
Important
\
properties
The rocks and mmerals shown are raw materials
Important to us because of them properties
*<
@
c+
c
These rocks are
Sandstone
metals can be extracted
from theee mmerals
I
Malach~te(cent.wm
copper)
4s
Haematlte
for electrical
wrong
(contains
iron)
for conatructlon
For each example above write down
●
why they are useful raw materials
..-
mat&lals
r
t-o
Plan a vmt to your local mme or quarry
Fmd out what M mined and how to get there
63
-—.-
210
TopIc
B3
Lwlng organmms and then: environment
9 What WIIIbe the effect
a onwild flower populatwnsand
bon
Fq.
10
the y!eld of soma crop Plants
If polhnatmg resectsare accldantally kdled by msact!cldes?
Many resectsare predators of certain resect pests (figure 177) If the
farmer’smsect!cldekdls them as wellas the pests, then later on, If the pests
return, there may be too fewof theu predators left to control the]r numbers
C
Nowadays manufacturers can make pestlc]des that only harm one
particular pest - they are called speczfic pesticides
A persistent
Figure 178
E..h hmc a m,nnow ate a phmktO.
orga.mm II took n hny dose or DDT
The dose stayed m the mmnows bcdy
,nd b.!ll up as the m,nnow ate mOr.
A p,ckcrcl fish rece,ved however m..h
DDT had bud! up !n a mmnow’s body,
cuch mm II .1. a m,nnow
Herons .!c m,”nows a“d small p,ckercl,
as WCIIas other fish 0... again DOT
bu,ll up ,. thetr bodms .s they rccermd a
dos. rrom each fish eaten Th!s dose was
N,”
I,WW
ror the osprey and
corm. r,!nl, because Ihcy eat sIIII
b,ggcr hsh
The Icvd or ODT I“ {h. cormorant was
500000 i,nlcs h,gher ~han the Icv.1 Or
DDT I. lhc SC. waler
(The “umbcrs g,vc ihc rxrce.ta8e
co”cc”lrm,on or DDT )
nursance
Anotherserlou$ problem with pesticides concerns howlongthey last once
they are sprayed on to a crop Some decompose qumkly mto harmless
chemicals once they reach the soIl, or are absorbed by a plant Once this has
happened they no longer kdl orgamsms But many of the first eiTectlve
pesticides thal were made (such as DDT, aldrm and dleldnn) last for a very
long time m the environment They rctam the]r poisonous properties and we
CaII them pmi.~[cnt peslrcldcs When they were used they entered food webs
and became so concentrated m the t]ssues or the top consumers that these
an!mals were poisoned, the!r behavlour changed, their abdlty to reproduce
was lessened, and many of them d]ed Figure 178 shows how this happened
Many persistent pesticides accumulate m stored fat In the body of ammals
SCEIUISIS
have analysed the body fat of seals and pengmns m Antarctica and
have found pesticides m the hssue The neareat agricultural land to Antarct!cd
ISaround 1000km away There are no traces of pestlctdes m the fat of seal
carcasses that h~ve remamed frozen since they were kdled during the Scort
expedlt]ons to the Antarctic early thm century
-
p,ckml
em mnnows
and
oth,~
,oI”m, means [heyeas,lvabm~
b
, ~e,mde fromwater
,1 ,,”,,n,r,,,”g
,,mowms
m
L
1
I
v
16.2
Day and night
[[~, 12
Different lengths of day and night
The ams on which the Earth spins is en Imagmeq
north and south pole
hne through the
Th]s ams m at a tdt to the rays from the Sun to tha Earth
In the picture, three hnes have been drawn mound the Earth These
hrrea are called latitudes The latltude at the middle of the Earth M
called the Equator At the Equator, there are always 1z hours of
darkness end 12 hours of hght Bacause of the Earth’s tilt, other
lahtudes have a daylength which changes through the year
The posltlon of the Earth m June and December M shown here The
Earth’s tdt M always at the same angle Drawing the path taken during
one day’s spin, shows two things
N
N
summer
winter
s
s
In June, the north pola Is fsa!ng towarda the aun
Ths nonhsrn hemlsvhsrs has a IOnOlenti Of daylight ads
time m dsrfmess
(long dsys, ahotl nights)
In Decembsr, the north pole Is fadng away from ths Sun
The mnllrern hemmphere hass short length of dayhght and a long
time In datinesa
9h0fl
(shorl days, long nights)
(not to scale)
..
Use the drawing to axplain
why the northern hemisphere
has long mghts m December
end short mghts m June A
2 How wdl the lengths of day
and mght very m the southam
hem]sphare?
3 In March and Septamber the
Earth’s SXMdoes not tilt
towards or away from to the
Sun What does tim tell you
about the length of day and
mght at these hmes of the
year?
4 ‘l& to find out whare
Sp:tsbergen M end explain
why the Sun ehmes at
mldrught there m June
1
Dld yOU kllOW?
The Earth’s us pomte to a
poration in tbe sky near to
the pole star [Polens)
However, the Earth
!wobbles’ ahghtly on Its
axis, ratier hke a spmmng
top wluch 1S shvrng
down It takes 25000
years for one wobble In
~~ 500 years the pole star
wdl not=be over the Earth’s
north pole, but It WIII be
back in place m 25000
yeersl
epltsbergen at midnightin June At this time
of the year the Sun never disappears
6
/
(TJ
I
\
1/
:
/,
‘1
‘k
/
Figure
13
Z-shaped gesture making video image analytical
What
makes
gases
useful?
Gases are useful because they are squashy
El
What would happen If alr
could not get past the washerp
Q The first bicycles had sohd
tyres Why are modern b]kes
d]fferent? (Think how a sohd
ball compares with a
balloon )
El Imagme your bqcle tyres
were fdled w]th water What
would It be hke to ride?
Y
Gases can be compressed
for storing.
Q Compressed means squashed
❑
Gases can be compressed
to do work.
up Why Mthe gas more
useful squashed up hke thlsp
Which other gases are stored
squashed up?
❑
What other]obs do we use
compressed gas forp
Gases expand when they are warm.
Expand means to spread out Try this experiment
●
●
●
●
●
z~7-KAs
~Anautomatlc
supermarket
door uses compressed av
(a) When does the door open?
(b) How does lt know when to
openp
(c) How does It know when to
close?
(d) How does the des]gner stop
people getting hurt m the door?
,:&(
l\
Get a flask with a narrow tube m the top
Run cold water over the outs]de to cool d
Hold the flask upside-down m both hands
so that the narrow tube dips mto some
water Watch carefully for a mmute
Now hold the flask m two fingers at Its
neck Keep the tube under water and
watch
Write the experiment up m your book and
exulam what vou saw
\“4i\
-
\\i,;
/ .. . .
w&
.—.
<
/Tiks
Omlpresso,
conrr.1
>
/ /
box
P.w
P,stonopensthe dcor
(e) Why doesn’t the compressed
am run out?
zMOstUnderground
trams
have pneumatic doors
Pneumat]c means powered by
au How 1s the control of a tram
door different from the control
of a supermarket door? Why IS
there a difference?
77
,~
F.q {5
?eference section
t
‘lasslficatlon
r
T
‘~
t
—
T
+
M4NEUDS
.-arm-ha
.dd
-
h/:
,,
@
-1
l—
Es
a
DEW15
PROTI
,... —...
*&-
1
EAYOMYTAm
AM
\
@.-&(-)*.*
J
%
1
MIGw
I
I
34
I
135
73.78Folding .—
and faulting
Faulting
Folding
Layers
of rock were
Forces ,n the Earth
crumpled
“1 ‘6
lald down
pushed
up a blt like
Part of the crust hasshpped
This ,s known as a fault
The layers of rock have been tom and rearranged
by sedlmentatlon
on the layers
and they
paper
!
A fault In mck layers
folds m rock layers
mm
*&
Ingleborough
I
The surface of the Earth M
always moving These
movements are usually too
slow to see We only see
their effects In the rocks of
the Earth’s crust
The photograph
shows
Ingleborough,
a hdl m
Yorkshire It has been
formed over mdl,ons of
years by sedlmentahon,
foldlng, faultlng and
erosion The draw!ngs on
the opposite page show
what we think has
happened
20
-—
When you have frmshed
~ Make a chart showing the parts of a plant
cell and what each part does There 1s
some mforrnahon to help you below
More plant cells
Examme cells from some other plants
You need
Pieces of plant Microscope and other Items
as m previous mveshgahon
Useful mjmrrratlon
● Good plants to choose are privet leaves, ms
leaves, rhubarb stem
● You wdl only see cells ti you use a thm
piece of plant, such as the outer layer
vacuole
chloroplast
cytoplasm
nucleus
membrane
cell wall
stored Iood
(malrdy starch)
to do
Carry out your mveshgahon lust as you
dld for the onron cells
H Draw four cells from each plant
What
■
Paris 01a
Membrane
Looking at ammal cells
Look at the pictures of the ammal cells below
and answer these queshons
~ In what ways are the asumal cells slmdar
to plant cells?
~ How do they differ from the plant cells
you looked at?
~ It 1susually more dtifmult to examme
as-umal cells m school Can you think of
reasons why?
plantcell
A thm skm wh,ch lets food and other wtal
substances mto the cell and waste substances out
Vacuole This 1smaudy water When full, It keeps the
cell firm
Cellwall Helps the cell keep lta shape
CytoplasmThe chemical reachona which keep the cell
ahve happen here
Nucleus Tlus holds aff the chemical urstnrctlons about
the cell, Its characterlshcs and what It has to do
Chloroplasts
contanr
a green substance
.
.
nucleus
.,:,...
;.,
..::,
. .
cytoplaam
“““
.,.;:
,. . . .
@
x 3000)
chloro-
.
:~:,’t:
.,:,::’.
Human cheek cell (magnification.
called
phyll This traps the bght energy wh,ch plants need
when makmg food
.
,
,.,:..
..-
;,.
‘..%:
. ,.$,.1
;{;;
..,,
,
#q4
;...
.S.
membrane
stored Iood
vacuole
.? :.:
Paris of an ammal cell
105
, -,
h
‘L
.. ————
TopIc P4
212
Wavaa
object
tmage
N
Y
mc,dentI!ght
3-
---:+
,.<
----
---
/“
,//“
I
reflectedI,ght
ammarsto come
from here
mwor
reflectedIlgh!
Figure 7
When hght [reman obJcc[ISreflected by a
mmor [t [onns an Image The Image ISat
the point the reflected hght appears to
come from
/
I,ghtbeam
I some01thelhght,/’
I ISreflected
fl
/
811
/
I
,’
1/
glass
mosrnfrhehght
u rofracmd
+
F]gure8
Not all hgbt falling
on a glass surface
passes mm Lhc glass, some of It M rcflccred
Figure 9
All of (he mctures
d
them
‘ no]se”~
revolve sound In which
would you descr,tx the sound as
Images can be formed by regularly reflected hght Thrs IShow we can see
ourselves m a m]rror (figure 7)
When hght meets the surface of somethmg hke glass or water, some of the
hght passes mto It and some Mreflected (figure 8)
Sound
Sounds can vary greatly m mtenslty from very loud to very soft Sounds also
often have a quaht y that we call p]tch We talk of a mus]cal note being of h]gh
pitch or low pitch Sound with nn dmtmgrnshable pitch N called noise
Things wh]ch em]t sound are always found to be wbrafmg As you saw m
Chapter P4, a wbratmn Ma regular to-and-fro motion You may know
already that the number of wbrat]ons made every second Mcalled the
frequency The higher the frequency of wbratlon, the h]gher the p]tch of the
sound
Sound wdl travel through any substance (sohd, hqrud, or gas), but It wdl
not travel through empty space The speed of sound N ddTerent in ddTerent
materials For example, ]t travels much more qtnckly through a metal than
through am
Some revision
questions
for you to try
L-
CgN
Somevery small planta and anunale have only one cell,
but most planta and anmmls are made up of many cells.
Cells are very small In one cubic nulhmetre of human
blood there are more then five milhon cells!
Lq m
A hvmg cell has
chfferent
1 membrane wluch
controls the
movement of
substsncee m and
Most cells have
perta wluch
do MTerent
2 cytoplasm where
chenucal changes
Jobs
3 nucleus wluch
controls the cell
take place
out of the cell
m
●“
Dlm
wsf.1 wiuch
gwes the cd ehape
and SUp~rt
Most plant cells also
have
4 celf
5 chloroplasta wluch
mske fmd using
wiuch
holds a watery
solution
6 vacuole
a cells chagram and stick It mto your book
Label all the Important
parts of the ammal cell and the
plant cell
~,+i
2 Copy and complete the table below
CM.’*’
Phq*wl
tihal 1% Wt d~
,!$$
I
I
1 Collect
B
More cells
1 Make a shale of the green plant material
2 Look at the shale using the rmcroscope
@
47
Draw two of the plant cells Label SIX important
parts of the cells m your drawing
@
--
,
CM#’*’
FJ
—
F
P
‘c
‘*
L
.
@l’i”@
4 .
A switch
Electrmty
in time
flows around a cmcrmt The flow IS called a
current. The current goes through some matenala (such
as copper) more easdy than others (such as water) Water
has a iugher resistance than copper. When resistance IS
high, the current Mlow
The Idea of resistance helps us to solve some cmcmt design
problems For example,
● to make a svntch to turn the current
on and off (simple
smtch)
● to make a swntch to raise and lower the current
(&mmer
.wmtch)
1
1 Lmok at the smtch
Fmd out what happens
mmde the svntch when
lt operates
co/w
Smtches
fod
or I-W pull tops
Bulb
Battq
4 Cmux?Ctmg
w-u-en
2 cwmdlle Cllps
Metal
~—
Symtul j% a swich
2 Design and budd a cmc~t
mth a sumple mmtch m It
3 A rhmmer smtch makes a bulb dmmer by mcreasmg
the resistance to the current Budd the cmcmt below
Parb neededta
bmld the dunmer
smtch
Coppsrwe
Nwhromewue
A+ I+----l
/-’”
a Fmd out what happens when you change the length of
the wwe (length A)
b Fmd out what happens when you replace the ruchrome
wme mth copper wu-e Keep length A the same each
time
—
80
—r---m
E
,.’7
L@
L 1.5 Digesting food
Most of the food you eat has
to be changed before your
body can use ]t Scientists call
this process digestion
II
1‘“’’”T(
I
When you swallow food, It
enters a tube that starts at
your mouth and ends at your
anus This tube IS about ten
metres long It 1s often called
the gut
~ Look at the diagram of
the human gut Move
your finger along It,
tracing the path that a
piece of food would take
~~ List, m order, all the parts
that a piece of food would
pass through
gall
Ihve
Dan
~deum
Some organs are linked to
the gut by tmy tubes along
which hquld can flow
~~ Write down any organs
hke this which you can
see m the diagram
I
anus
-
<co’””
1
model gut
Fmd out what happens to some food
(glucose and starch) when Its put mwde
a model gut made from Vsskmg tubing
You need
V~kmg tubing (about 10 cm long), mixture of glucose, starch and water, beaker,
dropper, chemicals and eqtupment to test
for starch and glucose (see mvestlgahons
m the prewous spread L1 4)
..
large
mleslme
Useful mformatlon
You can see a model gut m the diagram on
the right The tubing IS the gut The water
outside It 1s the ‘blood’ (water makes up a
large proporhon of real blood)
What to do
Make and set up your model gut You can
fdl the Vlskmg tubing using the same
method as you dld m L1 4
■ Test the ‘blood’ after fifteen rmnutes
■ Has any substance passed through the wall
of the gut and mto the ‘blood’~ If so, what?
w Has any substance not passed through the
wall of the gut7 If so, what?
■ Prepare
a report on your mvestlgahon and
what you discovered
■
110
r~
fectum
Iaeces stored
here belore
Ieavmg body
The human gut
Before It can be used by your body, food
must pass through the wall of the gut and
mto the bloodstream Thss mamly happens m
the small mtestme You can use a piece of
V1skmg tubing to make a model of the small
mtestme
1
small
mlestlne
Iood
\
[
A
+s”’’’O”’
—.
—
x ?&.
b 24
K2. 1 Changing state
Whenever a sohd changes to hquld or a Lcqtud
changes to gas, or the other way round, sc]enhsts say there has been a change of state
Answer these queshons with your group
What changes of state can you seem the
picture? List them
‘. Which of these words describes each of the
examples on your 1A?
erraporatmg,cmrdensmg, m.dtmg, sohd@rg
,1~What change of state occurs when somethmz freezes7
A
Turrung hquld
Imagme that you have a really cold drink
with lots of crushed Ice m It
n What do you think wrll happen to the
temperature of the drink as the Ice melts?
@ivest/ga~
■
Test your prediction Fmd out what happens to the temperature of some cold water
with meltmg Ice m It
You need
Crushed Ice, beaker, water, thermometer,
stopclock or watch
78
Things to think about
P How often wdl you measure the temperature?
u How wdl you record your temperature and
hme measurements?
What to do
Put some cold water and crushed Ice m a
beaker
■ Take the temperature
of the meltmg Ice
frequently Keep the mixture well stirred
all the hme
■ Plot a graph of your results
■ Do your predictions
agree with your
results7
■
Visual Communication in the Learning of Science
LIST OF FILES
Main
folders
Secondary
folders
File name
No.
File Description
2 Inclass/
glass
1,2
Year 8. Two interviews with different
groups in one class, conducted during the
class, on their understanding of procedures
6pairs/
Astronomy
3-8
Year 9. Six interviews, each with a pair of
students, on their responses to images in a
text they had been using in class.
Class/
Energy
9
Year 8. Post-class interview about ideas of
heat, energy and fuels.
Pair/
pressure
10
Year 9. Interview with a pair of students,
post-class, on their understanding of a
phenomenon and its graphic representation
Pair/
Textbooks
11
Year 9. Interview with a pair of students
on their responses to images in text-books
they had not used before
Interviews
(11)
Lessons
(23)
Astronomy
/David
Year 9. Series of six lessons in sequence
(below) about Earth in Space, with much
use of images, models and other
communicative modes
Astronomy 1
Astronomy 2
Astronomy 3
Astronomy 4
Astronomy 5
Astronomy 6
12
13
14
15
16
17
Single
lessons
Lesson 1
Lesson 2
Lesson 3
Lesson 4
Lesson 5
Lesson 6
Collected transcripts of individual lessons.
Ammonia/
Don
18
Year 8. Transcript of a lesson about
ammonia
Blood/Tom
Cells/John
19
20
27
Year 9. Transcript of a lesson about blood
Year 9. Transcript of a lesson about
biological cells
Year 7. Transcript of a lesson about
electric charges
Year 7. Transcript of a lesson about
electric circuits
Year 11. Transcript of lesson about the
endocrine system
Year 7 Transcript of lesson about handling
flames and working glass
Year 9. Transcript of lesson about the
lungs
Year 9. Transcript of lesson about matter
made of particles
Year 8. Transcript of lesson about the soil
Charges/
Janice
Electricity/
Olive
Endocrine
system/Rob
Glass/Martin
21
Lungs/Tom
25
Particles/
John
Soil/John
26
28
Year 8. Transcripts of two lessons (below)
about investigating fuels
preparing for the investigation
29
starting off the investigation
22
23
24
Fuels/Tom
Fuel Prep/
Tom
Fuel/Tom
Particles/
Tracy
Year 9. Sequence of two lessons (below)
about matter made of particles
Particles1/
Tracy
Particles2/
Tracy
30
31
Pressure/
John
Year 9. Sequence of three lessons (below)
about the idea of pressure
Pressure 1/
John
Pressure 2/
John
Pressure 3/
John
32
33
34