• Use your senses to observe
-be objective (measure), not subjective (opinions)
– See, hear, touch, taste, smell, etc.
• Can also use tools to measure (label numbers)
– Temperature, length, volume, etc.

• Qualitative – describe what we observe
– EX: The flower has white petals.
– EX: Bob has blue eyes.
• Quantitative –measure what we observe
– EX: The flower has seven petals.
– EX: Bob has two eyes.

Try to make quantitative observations out of qualitative ones.
• Qualitative: The dead fish is smelly.
• Quantitative: You could ask a person to rate the “smelliness” from 1-5.

1. Be specific
2. Use numbers
3. Use terms others would understand
4. Avoid using emotions, good/bad, or opinions
5. This is not the time for critical evaluations…just state the facts.

• Reasonable conclusions or a hypothesis from observations you’ve made.
• Use judgments based on past experiences or and prior knowledge.
What inference can you make here?

• It is 58 o F in the room.
• It is cool in the room.
• The iguana likes lettuce.
• The iguana consumed 90% of the lettuce.
• The bacteria is yucky.
• The bacteria has a slimy appearance and smells of sulfur.

• “What is the effect of the independent variable on the dependent variable?”
• What is the independent variable here?
What is the dependent variable here?

• What is the effect of temperature on the height of plants grown in soil?
• How tall do plants get?
• Why does that fish always swim to the top?
• What is the effect of oxygen content on the water on the swimming location of a fish in a tank?

GET A DOZEN CRICKETS WITH A
CUP (hand on top)-Put them in the tank w/lid, please.
• Make at least 10 observations and 10 inferences
• Write Problem Statements related to the observation Obser vation
Infere nce
Proble m Stat.
1
2
3
4

• Laptops, if needed
• Refer to your articles
• Plan for the cricket behavior experiment:
-problem statement
• -experiment set-up
• (Independent and
Dependent Variables)
• (Block - will run 3 trials, do test run

• “If…then…” If producing oxygen bubbles in photosynthesis is related to light color , then green light will increase photosynthesis oxygen bubbles to form.
• Independent variable-varied by experimenter
• Dependent variable-changes as a result of the independent variable
• Prediction

• 1. Must be testable – some way to check its validity
• 2. Must be falsifiable – must be some experiment that could show that it is not true (may not prove to be false, just have to be able to test that)

Can you test these to be falsifiable?
Can you rewrite these to be testable?
• 1. Animals are better than plants.
• 2. The average tree height on the HS campus is the same as on the MS campus.
• 3. How many angels does it take to dance on the head of a pin?

• Common Hypothesis
• - educated guess
• - the general statement
• Formalized Hypothesis Write the “If … and then…” format
• DO WORKSHEET TO PRACTICE WRITING
IF…THEN HYPOTHESES

Writing a problem statement and hypothesis for your cricket behavior tips:
•
Sexual : male vs. female
•
Phototaxis : how many crickets in diff. light
•
Stimulus : food or terrain preferences
•
Courtship : make a chart of beh. (touch, chirp, face direction, mount)
•
Agonistic : make chart of beh. (bite, jump toward, chirp, etc.)
•
Territorial: count crickets in areas (hut, leaves, by water, by food, by females)

• Only one tested variable at a time
• Manipulated Variable (Independent
Variable) – one you change
• Responding Variable – (Dependent
Variable)- one that changes as a result

A. Independent Variable -what you change goes on the X-axis of the graph
B. Dependent Variable -what changes as a result of what you did – goes on the Y-axis of the graph

Independent Variable?
Dependent Variable?

•
Constants -all the things in the experiment that stay the same same size Petri dishes
Same agar medium
Same type of bacteria

What constants are there in this experiment?

– the part of the experiment that does not have the independent variable in it
• Use for reference, comparison
• Often the normal condition (no food, room light, room temp.)

L-added oxygen
M-control(no gas added)
R-added carbon dioxide

Do you think a placebo is a control?
(inert pill, one without the drug)
• EX: some take Celebrex®, some take a sugar pill

graphs charts video write observations measurements

Celebrex – Placebo Experiment
Results
• Have we proven that
Celebrex® (without a doubt) improves arthritis pain?
• What might be another explanation? Can we prove it false?
450
400
350
300
250
200
150
100
50
0
Celebrex Placebo
Improve
Same

•
The 10% spray produced taller plants.

Other scientists must be able to repeat your experiment with similar results to prove it true. OR they might prove it false.

NOW YOU WILL DESIGN AND
RUN AN EXPERIMENT
• RECEIVE CRICKET BEHAVIOR
EXPERIMENT HANDOUT
• LAB GROUPS OF 4 (5)
• BEHAVIOR VARIABLE
• PLAN SET-UP
• RUN 3 TRIALS
• WRITE RESULTS

•
August 25(Mon.) – Cricket Fact Sheet
•
August 25/26 (M/T)-Observe crickets
•
August27-29(w/Th/F)-Design + Run Exp.
•
Sept. 5 - (Fri.) Cricket Report Due