IV on X axis, DV (outcome) on Y axis Stable: subjects who exercised more every month over a year had the same amount of hair loss as those who worked out less Ascending: as income level increases, SAT scores also increase Descending: as driving practice hours increase, occurance of accidents decreases Variable: as the amount of sugar consumed increases, hours of sleep is variable
...or unrecognized variable (maybe two different animals made tracks on top of each other - they&apos;d be hard to distinguish)? ...or no control (you couldn&apos;t tell what&apos;s causing a change)
What do these boards have going for them?
Actually, this is MOSTLY correct. But the description of a scientific LAW is misleading and, well, wrong. This just proves an important point, that you should not always believe everything printed in textbooks!
NOT theory becomes law becomes fact *example: we SEE a rock rolling down a hill that smashes into a brick wall, we EXPLAIN what we saw by theorizing about gravity (an unseen force that pulls the rock down the hill), and we DESCRIBE the motion of the rock by using the formula F=ma
Science Inquiry: Conclusion and Presentation
Conclusion & Presentation
Bonus: Your DV data ranges from 0 to 37 worms (per square
meter). On a grid with 30 boxes along each axis, what value
should you assign to each box?
- 1.5 or 2 worms per box (always round UP to fit your range of numbers)
1. What is the average of this data set: 23 mm, 4 mm, 98 mm, and 37 mm ?
• 40.5 mm (23 + 4 + 98 + 37 = 162 ÷ 4 = 40.5 mm )
1. On which axis should the manipulated variable (IV) be placed?
• X-axis (and the DV should be on the Y-axis)
1. What is the difference between quantitative and qualitative data?
• Qualitative describes what type (with categories or verbal descriptions)
• Quantitative describes how much or how many (with numbers)
1. True or False? Qualitative data should be displayed on a scatter plot line
• False (a bar graph or pie chart should be used)
1. What should always be included in the label of each axis on a graph?
• UNITS!!!!! usually in parentheses: (mm) or (in grams) or (%)
In your lab notebook, please answer as best you can:
Data Presentation Checklist
Does your graph have a descriptive TITLE at the top?
Does each axis have a LABLE with UNITS?
Did you start the numbering on each axis at zero (0)?
Did you spread numbers out evenly along each axis?
Do the numbers in your data table and numbers on
your graph match?
• Graphs are often
used to show the
variable and the
1. exercise/hair loss
3. driving practice/
• After explaining what your data shows, state
– Summarize your results (share average values) in a way that
relates the numbers to your original scientific question.
– Restate/rephrase your hypothesis as past-tense, filling in
what actually happened.
– Tell whether your data supports or contradicts your
• The measurements, when compared, showed an average 1.6 mm
difference in length and .8 mm difference in width. The cast was
almost identical in shape, but did not fit into the mold of the
hypothesized animal because it was 7 mm smaller in width and 4
mm shorter length-wise. This does not support the hypothesis that
the animal tracks were made by a skunk.
• If hypothesis is rejected
– modify your hypothesis and perform another experiment
• If hypothesis is supported
– the experiment should be repeated to verify results
• Either way, something was learned!
– NEVER make up results simply because you
think it was “supposed” to go differently
– NEVER change your hypothesis before forming
What if My Hypothesis was Wrong?
• EVERY experiment has errors
– Uncontrolled variables
• Weather, animal behavior, unexpected interruptions
– Data collection errors
• Inconsistent methods, accidents, contamination
• Sloppy recording (can’t read writing, mixed numbers)
• Be sure to record and note in your conclusion
all errors and ways they could be corrected in
• Include plans for further experimentation
– Revisions: what would you do different next time?
– New questions: revised hypothesis or different
(but related) questions to investigate.
• Include WHY you want to
change things for your next
• Display most of the SI Packet info on a poster or tri-fold
• Make LARGE FONT titles for these sections:
– MATERIALS (list)
– RESULTS (your data table & graph)
• Colorful borders and graphics help info stand out.
• Include photos, models, equipment, video, etc.
Sharing Your Findings
1. State problem and
2. Formulate hypothesis
Fact - Theory - Law
F = ma
Fact - Theory - Law
– an objective, verifiable observation of something
that occurs in our natural world
– i.e. heat exchange, movement, gravity's effect,
natural selection, etc.
– an explanation of how natural occurrences work
• it can be observed, repeated, and tested with predictable results
• A tested hypothesis often explains part of a theory (theories often
incorporate many different hypotheses which are supported by much data).
– i.e. Theory of Gravity, Theory of Evolution, Kinetic Theory of Matter
– a verbal or mathematical description of observable phenomenon
– i.e. Newton's Second Law of Motion:
• or Newton's Third Law of Motion: "For every action, there is an equal and
• Definition: A law in science is a generalized rule to
summarize a body of observations in the form of a
verbal or mathematical statement.
– Scientific laws imply a cause and effect relationship
between the observed elements and must always apply
under the same conditions.
– Scientific laws do not try to explain 'why' the observed
event happens, but only that the event actually occurs the
same way over and over.
• Kepler’s Laws of Planetary Motion
• The Law of Conservation of Mass
• Newton’s Universal Law of Gravitation