2014 - 2015
Hayah International
Academy
Science Fair
All the information you need to participate in the annual Hayah International
Academy Science Fair. This document contains everything you need to get started
including all rubrics and deadlines for the project.
Aliaa Samaha
Hayah International Academy
2014 - 2015
Contents
General Information ................................................................................................................................................ 2
Deadlines................................................................................................................................................................. 2
Guidelines for Writing the Report: ........................................................................................................................ 3
The Scientific Method............................................................................................................................................. 4
Project titles: ........................................................................................................................................................... 5
Rules and Regulations: ........................................................................................................................................... 8
Guidelines for constructing your display chart: ...................................................................................................... 9
Oral Presentation:.................................................................................................................................................. 10
Report Rubric ........................................................................................................................................................ 12
Glossary: ............................................................................................................................................................... 13
General Information
Hayah Academy’s Annual Science Fair is a very important part of your science education. It draws together not
only the scientific content you have been learning, but also how scientists investigate and communicate their
work on these topics.
The Science Fair project will be graded as part of Quarter 3 science grade and is split into three parts:
PART 1: Report – 64 marks
PART 2: Display – 24 marks
PART 3: Presentation – Competition
Part three is not graded, but the highest achievers will be entered into the final for the science fair and have a
chance of taking home the prize, trophy and glory of being crowned ‘Hayah Science Fair Champion 2015’.
This is a piece of work that, although forming part of your quarter 3 science grade, will be assessed almost
continuously from quarter 1.
You will receive feedback on each section after handing it in and then have additional time to make any
changes suggested by your teacher until the final deadline it is due.
Teachers spend an awful lot of their time providing you with constructive feedback on how to achieve a better
grade. Please make sure you read this and act on the suggestions they give you.
Deadlines
For each of the sections below, you will have an initial due date. After this your teacher will provide feedback
on how well you have done. If you miss the initial due date you will NOT get feedback from your teacher. After
feedback you will have time to improve your work before the final deadline. If you miss the final deadline that
section will lose 20% for being one day late, 40% for being two days late and will score 0 if it is more than 2
days late.
The deadlines below are non-negotiable. If you are away at a tournament etc. it is your responsibility to hand
your work in before the deadline. In the case of sickness, the work should be submitted on the morning of
when you return to school before homeroom.
You may or may not have a science lesson on the following due dates. Your work is to be handed in anyway.
It is your responsibility to find your teacher on that day and hand them the work between the hours of 7:30am
and 3:15pm. Any work submitted outside of these hours is considered late.
Strand
Hypothesis, Variables &
Predictions
Procedure and Risks
Initial Date Due
November 12th 2014 (Day 5)
Teacher Feedback Due
November 20th (Day 4)
Final Deadline
November 27th (Day 2)
December 4th 2014
(Day 1)
December 11th (Day 6)
December 17th (Day 4)
Data Collection, Physical
Evidence Chart, Data
Analysis, & Secondary Data
Conclusion, Evaluation,
Display
February 8th (Day 4)
February 16th (Day 2)
February 22nd (Day 6)
March 1st (Day 4)
March 8th (Day 2)
March 17th (Day 3)
April 15th (Day 5)
Guidelines for Writing the Report:
The written report of your project must include all the following items with the title for each item as
underlined below.
1. An accurate, descriptive Title.
2. A statement of the Hypothesis being investigated which includes both independent, dependent and
control variables.
3. A list of Background Information that you might have about the problem being investigated including:
a) A description of what you knew about the problem before your investigation.
b) A statement of why you think the problem is important enough for you to investigate.
4. A Prediction of what you think will happen and why.
5. A list of all the Material and Equipment you used in your project.
6. A step by step Procedure you followed.
7. A table of the Results you obtained during the investigation.
8. A Graph or chart of your results with error bars, correct scales and labels.
9. An Analysis of your data, was it reliable, accurate, precise and valid?
10. A statement of logical Conclusion that reflects the data collected. Was your hypothesis correct? How
do you know? You MUST include data in this section and refer to your graph.
11. A comparison of Secondary data. Has anyone else done this investigation? What did they find out?
12. An explanation of the Importance in our daily lives of your investigation and your results.
13. A list of suggestions for Further research.
14. A list of References that you used.
15. A list of those people who contributed to or helped you with your project.
For more information on each of these sections and what to include in them, see the next page on the
scientific method.
The Scientific Method
A science project is your attempt to study a scientific problem in order to answer a proposed question or
develop a better technique or final product. Science projects involve research and test to arrive at a specific
conclusion. The basic procedure involved in science projects is modeled in a process called the scientific
method. This method consists of the following elements: hypothesis and variables, prediction, procedures
and risk assessment, collecting data, organizing data, analysis of data, research of secondary data, conclusion
and evaluation. Each element may be defined as follows:
Hypothesis: The problem or question for which you are seeking a solution. (Example: How can I help my plant
grow greener?) – A scientifically testable question outlining the variables you will use.
Prediction: The solution to your question. (Example: I think that if I add fertilizer I can make my plant grow
more by 20%) – it should include numbers and a reason why you think this (you can do research here)
Procedures: This is a step by step method of exactly how to perform your experiment. Be detailed but concise.
Risk assessment: You must consider all of the things that may go wrong that might hurt yourself or others in
your experiment. Think about how you would control the risks and plan what you would do if the worst
happened. MSDS sheets can help here for chemicals.
Collecting data: This is your results table. Make sure it has headings, units and is clear.
Organizing data: Your results need presenting in an easy to read format such as a graph or bar chart.
Remember to include a line of best fit, units, labels and error bars.
Analysis of data: What does your data show? Can you trust your data? Is it reliable, precise, accurate and
valid? (Quick tip: you can’t analyze data without including some numbers from your results!)
Research of Secondary data: Who else has done this experiment or one similar? What did they find out when
they did it? Does it agree or disagree with your findings? Are you going to trust their data? Was it collected
properly?
Conclusion: This is where you get to sum up and say what the data is telling you. Again, you must include data
(numbers) from your results. Talk about the reasons behind the data using science…Why did the plant grow
more when it was given fertilizer? What did it do to the plant? You also need to explain how your findings help
us in our daily lives.
Evaluation: Possibly one of the most important sections. This is where you get to look at your experiment and
data with critical eyes. Did you do the experiment properly? Was the equipment good enough and did
anything go wrong? You can then suggest a way that you would do it differently next time to get better
results. You can also include what further research you would do to double check your results.
References: All of your research and anything that you didn’t write needs to be correctly referenced using the
Harvard style of referencing. For more information on referencing see the following website:
http://libweb.anglia.ac.uk/referencing/harvard.htm
Project titles:
The list of available projects will be as follows and will be allocated on a first come, first served basis:
1. How does the temperature of a tennis ball affect the height of its bounce?
2. How does the air pressure of a soccer ball affect how far it travels when kicked?
3. Which increases your heart rate more: walking up and down real stairs or using a stair-master?
4. How does a shampoo’s brand affect the strength of hair?
5. How does the type of material affect how long a shirt takes to dry?
6. Which nail polish best resists chipping?
7. How does the fat content of cheese affect its stretchiness?
8. How will the time spent chewing bubble gum affect its bubbles’ maximum size?
9. How will adding different flavours of Tang® to water affect the water’s boiling point?
10. What is the effect of toothpaste brand on teeth-cleaning power?
11. What brand of paper towel is most absorbent?
12. What brand of trash bag can withstand the most weight before ripping?
13. How does a light bulb’s wattage affect the amount of heat detected above a light?
14. Under what colour light do plants grow best?
15. Which brand of mouthwash kills the most bacteria?
16. How does brand affect ketchup’s flow?
17. Given the same amount of water, how does pot size affect the amount of time it takes to boil water?
18. How does the amount of yeast affect how high bread rises?
19. How does the type of container affect ice cream’s melting time?
20. Which can support more weight: paper or plastic grocery bags?
21. Does the brand of kitty litter affect clumping?
22. Does listening to one type of music lower heart rate more than another type?
23. How old does chewed gum have to be before it stops sticking to shoes?
24. Which frozen dessert melts slowest: ice cream, frozen yogurt, or sorbet?
25. How does the size of a drum affect its pitch?
26. How does a person’s age affect his or her ability to see at night?
27. How does hair’s curliness affect its strength?
28. How does the time of day affect your body’s temperature?
29. How does the type of music that a person listens to while exercising affect how hard he or she works out?
30. Which grows faster: fingernails or toenails?
31. Does gender affect lung capacity?
32. If you are right-handed or left-handed, do you also prefer a certain foot?
33. Does the material of the surface of a tennis court affect the height that a tennis ball bounces?
34. Does a no-name stain remover work just as well as a brand name?
35. Which is a better insulator: wool, cotton, or down feathers?
36. Does playing Sudoku puzzles improve your performance on other types of puzzles?
37. How does shutter speed affect the colour of a photograph?
38. How can you speed up the ripening of tomatoes?
39. What effect does watering have on how fast a plant grows from a seed?
40. How does gravity affect the direction of a plant’s growth?
41. How does the weight of a paper airplane affect its ability to fly?
42. How does a parachute’s material affect the speed at which it falls?
43. Which type of soap removes more grease: dish soap, hand soap, or shampoo?
44. What type of ground layers limit erosion most: sand, gravel, or soil?
45. How does the speed of a river’s current affect the size of the grains on the riverbed?
46. In what type of lighting does a plant grow best?
47. How does the type of seed in a birdfeeder affect the types of birds that the feeder attracts?
48. How does the material of a bandage affect its ability to stick after getting wet?
49. How does tire pressure affect a car’s fuel efficiency?
50. How does the amount of air in a balloon rocket affect how far it flies?
51. How does the type of string used in a “can and string” phone affect the phone’s ability to transmit sound?
52. Are rooms with carpeted floors noisier or quieter than rooms with wooden floors?
53. How does temperature affect the growth of mould?
54. How does meditation affect your heart rate?
55. How does the colour of a shirt affect the amount of heat it absorbs?
56. Do different types of onions make your eyes tear up more than others?
57. Which is better at cleaning mould and mildew: vinegar or commercial cleaning agents?
58. Does maple syrup’s “grade” affect its flow?
59. Do different brands of batteries last longer than others?
60. Which uses more water: a shower or a bath?
61. Which type of cup will keep a hot drink warm longer: paper, plastic, Styrofoam, or glass?
62. Is a person’s favourite subject in school influenced by gender?
63. Which type of fertilizer helps plants grow taller?
64. Is there a correlation between gender and the number of push-ups that a person can do?
65. Do best friends have the same favourite colour?
66. Are kids more likely to be influenced by ads that feature other kids or by ads that feature adults?
67. Does the amount of time a student spends watching TV affect his or her grades?
68. Which stains dentures more: coffee, soda, or grape juice?
69. Does the use of flippers help a person swim faster?
70. Do you wake up feeling more alert when you awaken to an alarm clock that buzzes, plays music, or plays nature
sounds?
71. Can blindfolded people tell the difference between bottled water and tap water?
72. How does a person’s age affect reaction time?
73. How does caffeine affect people’s heart rate?
74. Do some materials conduct heat more than others?
75. How does the roughness of sandpaper affect its ability to smooth various surfaces?
76. How does increasing the height of a ramp affect how far a ball rolls down the ramp?
77. How does the strength of a magnetic field vary with the magnet?
78. Can people identify their pet dog by the sound of its bark alone?
79. Do people who exercise regularly have a greater lung capacity?
80. Can people use their sense of hearing alone to tell apart a penny, nickel, dime, and quarter?
81. How often can people accurately tell if someone is happy, sad, or mad just by looking at the person’s eyes?
82. Can people correctly determine if a person is left-handed or right-handed just by looking at the person’s
handwriting?
83. What melts ice the fastest: sand, cat litter, or mineral rock salt?
84. Does temperature affect the growth rate of shoots on a potato?
85. Which best helps prevent soil erosion on a slope: plants, rocks, or mulch?
86. Does one brand of antacid neutralize acids faster than another?
87. Do gym shoes have more bacteria than sandals?
88. Do mildew-resistant shower curtains really keep mildew away longer than regular shower curtains?
89. Does a person’s weight vary throughout the day?
90. Which lightens stains better: vinegar or lemon juice?
91. Do fans really make you cooler or do they just make you feel like you’re cooler?
92. Can you judge depth as well using just one eye than using two?
93. Does your “handedness” have any relation to which eye is stronger?
94. How does your sight affect your balance?
95. Do plants inside a mall grow faster under artificial light or under a skylight?
96. Does washing your hands reduce the amount of bacteria on them more than not washing?
Rules and Regulations:

All projects will be presented on the same chart
Type: Nasebian project chart boards (poster board or plywood)
Size: 100 cm x 70 cm board – see the display rubric for guidelines on how to make this.

No names are to be written on the display. All the names are to be written on the back of the display
with the class name, the grade level and the school name.

Physical evidence of the experiment MUST be included such as photographs of you conducting the
experiment

All project ideas are allocated on a first come, first served basis.

Any information used that isn’t your own should be properly referenced using the guide given above.
This is in line with the schools plagiarism policy.

All deadlines are non-negotiable and work is to be handed in regardless of if you have a science lesson
that day.

Work submitted after 3:15pm on the day of submission will be considered late.

One day late loses 25% of the grade, two days late loses 50% and more than two days late loses 100%
of the grade.

If the initial deadline is missed, teachers will NOT provide feedback on the work.

Throughout the project you are also being graded on Spelling, Punctuation and Grammar, which is
referred to as SPaG in the rubrics.

All reports MUST be typed in font size 11 in either Calibri or Times New Roman. No other fonts or font
sizes will be accepted.
Guidelines for constructing your display chart:
Your project display will communicate to others what your project was all about. The display should be threesided and have a brief description of the various parts of your investigation. Adapt and decorate your display
to make it the best for your own project. Get one Nasebian chart board (100cm x 70cm). Cut one side of the
board at 25cm in on each side so that it folds. Note that the height is 70cm, middle board is 50cm and each of
the foldable wings is 25cm in length.
50cm
25cm
Hypothesis
Data Analysis
Results table
_______________________________________
_______________________________________
Background
_______________________________________
_______________________________________
___________________________________
___________________________________
___________________________________
_______________________________
___________________________________
___________________________________
2.
3.
4.
___________________________________
___________________________________
___________________________________
_______________________________
___________________________________
___________________________________
_______________________________________
_______________________________________
____________________________________
_______________________________________
_______________________________________
____________________________________
_______________________________________
Conclusion
Graphs & Charts
Method
1.
25cm
A clear and descriptive Title
_______________________________________
_______________________________________
__________________________________
________________________________
__________________________________
________________________________
__________________________________
________________________________
__________________________________
________________________________
70cm
Secondary data
_______________________________________
_______________________________________
____________________________________
The following table shows exactly how your display will be graded. Where do you think you are on each of
the sections?
CATEGORY
4
3
2
1
Size
Display is of correct size
Display is of wrong size
Title
Title can be read from 2 m Title can be read from 2 m Title can be read from 60
or 6 ft. away and is quite or 6 ft. away and describes cm or 4 ft. away and
creative.
content well.
describes the content
well.
The title is too small
and/or does not describe
the content of the poster
well.
Attractiveness
The poster is exceptionally The poster is attractive in
attractive in terms of
terms of design, layout
design, layout, and
and neatness.
neatness.
The poster is acceptably
attractive though it may
be a bit messy.
The poster is distractingly
messy or very poorly
designed. It is not
attractive.
Required
Elements
The poster includes all
All required elements are
required elements as well included on the poster.
as additional information.
All but 1 of the required
elements are included on
the poster.
Several required elements
were missing.
Labels
All items of importance on
the poster are clearly
labeled with labels that
can be read from at least 1
m or 3 ft. away.
Several items of
Labels are too small to
importance on the poster view OR no important
are clearly labeled with
items were labeled.
labels that can be read
from at least 1 m or 3 ft.
away.
Total / 20
Almost all items of
importance on the poster
are clearly labeled with
labels that can be read
from at least 1 m or 3 ft.
away.
Score
Oral Presentation:
Based on the grades for the display and your report, the top 3 students from each class will have the
opportunity to present to a panel of three judges made up of science teachers. The overall winner of the
competition will then be decided on the basis of their presentation score as well as the report and display.
Below you can find the rubric for how your oral presentation will be scored.
CATEGORY
4
3
2
1
Volume
Volume is loud
enough to be heard
by all audience
members throughout
the presentation.
Volume is loud
enough to be heard
by all audience
members most of
the time.
Volume is loud
enough to be heard
by all audience
members some of
the time.
Volume often too
soft to be heard by
all audience
members.
Posture and Eye
Contact
Stands up straight,
looks relaxed and
confident.
Establishes eye
contact with
everyone in the
room during the
presentation.
Stands up straight
and establishes eye
contact with
everyone in the
room during the
presentation.
Sometimes stands up
straight and
establishes eye
contact.
Slouches and/or
does not look at
people during the
presentation.
Speaks Clearly
Speaks clearly and
distinctly all the
time, and
mispronounces no
words.
Speaks clearly and
distinctly most of the
time, but
mispronounces one
word.
Speaks clearly and
distinctly some
time. Mispronounces
no more than one
word.
Often mumbles or
cannot be
understood OR
mispronounces more
than one word.
Organization
Information is
presented in an
organized and
engaging sequence.
Information is
Limited organization Little organization is
presented in an
is evident in the
evident in the
organized sequence. presentation.
presentation.
Content
Shows a full
Shows a good
Shows a good
understanding of the understanding of the understanding of
topic.
topic.
parts of the topic.
Does not seem to
understand the topic
very well.
Comprehension
Student is able to
accurately answer
almost all questions
posed by judges
about the topic.
Student is unable to
accurately answer
questions posed by
classmates about the
topic.
Student is able to
accurately answer
most questions
posed by the judges
about the topic.
Student is able to
accurately answer a
few questions posed
by the judges about
the topic.
Total for oral presentation=
Score
/24
0
Evaluation
Conclusion
Secondary
Data
Data
Analysis
Chart
Data
collection
& Physical
Evidence
Procedur
e & Risks
Hypothesis
& Variables
Strand
Strand
0
1
2
3
4
Make a prediction to test but without
saying why you think that. Your report
may be short, have lots of spelling
mistakes and very few scientific words.
Includes an acknowledgment list.
Come up with a testable hypothesis and
say why you think it using common
sense or previous experience. Some
scientific words are used but spelling,
punctuation and grammar are not great.
You follow a method you were given or
got off the internet. In your report you
mention how you made the experiment
safe.
Select and use basic equipment to
collect a limited amount of results.
Correctly identify hazards that were in
your procedure.
Record a very limited amount of data (eg
individual points with no clear pattern),
covering only part of the data needed with no
checking for repeatability. Data is generally of
low quality. Includes physical evidence
5
6
7
8
Consider all the things that could affect your
results (variables) and use scientific knowledge
to make a testable hypothesis about how one
factor will affect the outcome. Your report has
a nice, flowing sequence and uses scientific
words. Your SPaG are good
Select and use techniques and procedures
appropriate for your experiment and say why
you chose the ranges you did. Identify any
significant risks and suggest precautions.
After talking about all major factors, select one and
propose a testable hypothesis and quantitative
(numbers) prediction about how it will affect the
outcomes. Your report is detailed; no spelling or
grammar mistakes and is in a sensible order.
Record enough data allowing some
errors in units or labelling and with little
checking for repeatability. Data is
inconsistent with some obvious errors.
Includes physical evidence
Collect and correctly record data to cover the
range needed, with regular repeats or checks
for repeatability. Data is of generally good
quality. Includes physical evidence.
Choose a big enough range of values to test with regular
repeats and appropriate handling of any outliers. Checks or
preliminary work are included to confirm or adapt the range
to generate sufficient relevant data. Includes physical
evidence.
Display limited numbers of results in
tables, charts or graphs, using axes or
scales that were given to you.
Construct simple charts or graphs to
display data in an appropriate way, with
some errors in scaling or plotting.
Correctly select scales and axes and plot data
for a graph, including an appropriate line of
best fit, or construct bar charts or diagrams.
Indicate the spread of data through scatter graphs (or
error bars) and give clear keys for displays involving
multiple data-sets. No errors in scaling. All units are
included.
Talk about accuracy or repeatability but
without any reference to the data.
Talk about individual results which are
beyond the range of experimental error
(are outliers), or say why you think
there are no outliers.
Use the general pattern of results or difference
between repeats as a basis for assessing
accuracy and repeatability.
Consider critically the repeatability of the evidence,
accounting for any outliers. Think about your method,
equipment, range and human error.
Compare your results with at least one
piece of secondary data and make basic
comments on similarities and/or
differences. Mentions how the project
applies to real world ideas or scenarios.
Identify in detail similarities and
differences between your data and
secondary data. Secondary data sources
are referenced, although these may be
incomplete. Describes some importance
of the project to the real world.
Talk about how much the secondary data
supports, or undermines your data, and
identifies any areas of incompleteness. A range
of relevant secondary data is collected from
several fully referenced sources. Explains how
the project is important in our daily lives.
Assess how much you can trust the available data,
and explain the reasons for making these
assessments. Comment on the importance of any
differences or similarities. Evaluates the importance
of the project looking at the impact it has on our daily
lives.
Correctly state whether your hypothesis
is supported, only using common sense
or previous experience. The response is
simplistic, with lots of errors in spelling,
punctuation and grammar and has little
or no use of scientific words.
Comment on whether patterns in the
data support the hypothesis and
suggest why using science. Some
relevant scientific terms are used
correctly, but spelling, punctuation and
grammar are of inconsistent.
Explain how much the hypothesis can account
for the patterns shown in the data. Use
relevant scientific knowledge to conclude
whether your hypothesis has been supported.
Information is organised effectively with sound
SPaG. Scientific words are used properly.
Give a detailed account of what extra data could be
collected to increase confidence in the hypothesis.
The report is comprehensive, relevant and logically
sequenced with full and effective use of relevant
scientific words. There are few, if any, grammatical
errors.
Make relevant comments about
problems you had while collecting data.
Describe the limitations of the
techniques and equipment used when
doing your experiment.
Suggest (in outline) improvements to materials
or techniques; or explain why the method used
gives good enough data to allow you to make
conclusion.
Describe in detail improvements to the materials or
techniques, or alternative ways to collect the data,
and explain why they would be an improvement; or
explain fully why no further improvement could be
achieved.
1
Report Rubric
2
3
4
5
6
Justify why you chose the equipment and technique
you did to achieve data which is precise and valid.
Complete a full risk assessment, identifying ways of
minimising risks associated with the work.
7
8
Glossary:
Accuracy
A measurement result is considered accurate if it is judged to be close to the true
value.
Calibration
Marking a scale on a measuring instrument.
This involves establishing the relationship between indications of a measuring
instrument and standard or reference quantity values, which must be applied.
For example, placing a thermometer in melting ice to see whether it reads zero, in
order to check if it has been calibrated correctly.
Data
Information, either qualitative or quantitative, that has been collected.
Errors
See also uncertainties.
- measurement error
The difference between a measured value and the true value.
- anomalies / outlier
These are values in a set of results which are judged not to be part of the variation
caused by random uncertainty.
- random error
These cause readings to be spread about the true value, due to results varying in
an unpredictable way from one measurement to the next.
Random errors are present when any measurement is made, and cannot be
corrected. The effect of random errors can be reduced by making more
measurements and calculating a new mean.
- systematic error
These cause readings to differ from the true value by a consistent amount each
time a measurement is made.
Sources of systematic error can include the environment, methods of observation
or instruments used.
Systematic errors cannot be dealt with by simple repeats. If a systematic error is
suspected, the data collection should be repeated using a different technique or a
different set of equipment, and the results compared.
- zero error
Any indication that a measuring system gives a false reading when the true value
of a measured quantity is zero, eg the needle on an ammeter failing to return to
zero when no current flows.
A zero error may result in a systematic uncertainty.
Evidence
Data which has been shown to be valid.
Fair test
A fair test is one in which only the independent variable has been allowed to affect
the dependent variable.
Hypothesis
A proposal intended to explain certain facts or observations.
Interval
The quantity between readings, eg a set of 11 readings equally spaced over a
distance of 1 metre would give an interval of 10 centimetres.
Precision
Precise measurements are ones in which there is very little spread about the mean
value.
Precision depends only on the extent of random errors – it gives no indication of
how close results are to the true value.
Prediction
A prediction is a statement suggesting what will happen in the future, based on
observation, experience or a hypothesis.
Range
The maximum and minimum values of the independent or dependent variables;
important in ensuring that any pattern is detected.
For example a range of distances may be quoted as either:
"From 10cm to 50 cm" or "From 50 cm to 10 cm"
Repeatable
A measurement is repeatable if the original experimenter repeats the investigation
using same method and equipment and obtains the same results.
Reproducible
A measurement is reproducible if the investigation is repeated by another person,
or by using different equipment or techniques, and the same results are obtained.
Resolution
This is the smallest change in the quantity being measured (input) of a measuring
instrument that gives a perceptible change in the reading.
True value
This is the value that would be obtained in an ideal measurement.
Uncertainty
The interval within which the true value can be expected to lie, with a given level
of confidence or probability, eg “the temperature is 20 °C ± 2 °C, at a level of
confidence of 95 %.
Validity
Was there only one independent variable affecting the outcome of the
experiment. If there was more than one thing changing the experiment is not valid.
Valid conclusion
A conclusion supported by valid data, obtained from an appropriate experimental
design and based on sound reasoning.
Variables
These are physical, chemical or biological quantities or characteristics.
- categoric
Categoric variables have values that are labels. Eg names of plants or types of
material.
- continuous
Continuous variables can have values (called a quantity) that can be given a
magnitude either by counting (as in the case of the number of shrimp) or by
measurement (eg light intensity, flow rate etc).
- control
A control variable is one which may, in addition to the independent variable, affect
the outcome of the investigation and therefore has to be kept constant or at least
monitored.
- dependent
The dependent variable is the variable of which the value is measured for each and
every change in the independent variable.
- independent
The independent variable is the variable for which values are changed or selected
by the investigator.