Mealworm Lab Demonstrates experimental design principles and scientific method Explores a living organism’s response to environmental variables (Ecology topic)
Objectives After doing this laboratory, students should be able to describe some aspects of animal behavior and understand the adaptiveness of mealworm behaviors create a workable experimental design write clear experimental procedures conduct a peer review.
Pre-Lab: Observe Make notes on their general appearance, and movements about the dish. Do they seem to prefer one area over another, keep moving, settle down, or move sporadically? Try to make your observations without disturbing the animals in any way. You want to observe their behavior, not influence it or interfere.
Design the Study Which variable will you test? Test only ONE variable at a time Too many variables!!!! What are they???
Design the Study USE A CONTROL GROUP or comparative sets of data For behavioral studies, compare with known behavior in the wild
Design the Study Provide AT LEAST 10 replicates or organisms per experimental group Decide how to control variables
Select Data Collection Method Always define the factors sampled Take samples randomly Otherwise, sampling procedures may be biased
Select Data Collection Method Is the procedure valid? Is there a way to quantify the data?
Write an Experimental Plan State the primary objectives Include a rationale and justification State the general procedures you plan to follow List any materials/equipment State what results you expect to get
Complete an ExD Template Problem: Hypothesis: Independent Variable (IV): Dependent Variable (DV): Control: Constants: 1) 2) 3)
Collect Samples Collect living specimens with care Don’t contaminate samples Avoid errors
Observe & Measure Samples Measure consistently Keep notes or in a log book Record errors
Sample Experimental Design Define the problem “The Effect Of Substrate On Mealworm Habitat Selection” Define the Independent Variable(s) Time in habitat chamber Define the Dependent Variable(s) Type of substrate
Creating an ExD Define the Experimental Group(s) Cut grass, wood chips Define the Control Group Chamber with natural humus substrate
Creating an ExD Make a Hypothesis If mealworms prefer the natural humus chamber, then they will stay there at least 80% of the time after the first 10 minutes of experimentation.
Creating an ExD Determine the Experimental Constants Moisture level, temperature, food, lack of predation Choose and Sketch the set-up
Creating an ExD Determine the number of trials or groups needed for validity 10 mealworms /chamber 10 thirty-second trials Determine how the results will be quantified # of mealworms/ chamber/30 sec
Write Up the Procedure 1) Prepare a choice chamber 2) Cover the bottom of each chamber with either wood chips, cut grass or natural humus 3) Transfer ten mealworms from the stock culture into each choice chamber 4) Cover the chambers
Write Up the Procedure 5) Count and record how many mealworms are in each chamber every 30 seconds for I0 minutes
Run the Experiment Quantitatively summarize data Make a Graph of the number of mealworms in experimental and control chambers per 30 second interval. Analyze the trend
Analyze The Results Interpret statistics properly DON’T make broad statements from small samples Not: This experiment proves that mealworms prefer pine needles as a substrate Instead: The results show that mealworms seem to prefer pine needles as a substrate)
Analyze The Results Compare data with other groups Analyze the trends Address errors Look at all alternative interpretations
Come to a Conclusion Validate the hypothesis Decide whether your data fits your hypothesis or whether you need further testing and revision.
Retest Re-test 100 times Peer Review Refine the experiment Example: Choose the same size mealworm
Pill Bug
Pill Bug Experimental Design Lab Experimental design is the way in which cause-effect relationships are discovered in science.
Pill Bug Lab Demonstrates experimental design principles and scientific method Explores a living organism’s response to environmental variables (Ecology topic)
Objectives After doing this laboratory, students should be able to describe some aspects of animal behavior and understand the adaptiveness of pillbug behaviors create a workable experimental design write clear experimental procedures conduct a peer review.
Pre-Lab: Observe Make notes on their general appearance, and movements about the dish. Do they seem to prefer one area over another, keep moving, settle down, or move sporadically? Try to make your observations without disturbing the animals in any way. You want to observe their behavior, not influence it or interfere.
Design the Study Which variable will you test? Test only ONE variable at a time Too many variables!!!! What are they???
Design the Study USE A CONTROL GROUP or comparative sets of data For behavioral studies, compare with known behavior in the wild
Design the Study Provide AT LEAST 10 replicates or organisms per experimental group Decide how to control variables
Select Data Collection Method Always define the factors sampled Take samples randomly Otherwise, sampling procedures may be biased
Select Data Collection Method Is the procedure valid? Is there a way to quantify the data?
Write an Experimental Plan State the primary objectives Include a rationale and justification State the general procedures you plan to follow List any materials/equipment State what results you expect to get
Complete an ExD Template Problem: Hypothesis: Independent Variable (IV): Dependent Variable (DV): Control: Constants: 1) 2) 3)
Collect Samples Collect living specimens with care Don’t contaminate samples Avoid errors
Observe & Measure Samples Measure consistently Keep notes or in a log book Record errors
Sample Experimental Design Define the problem “The Effect Of Substrate On Pillbug Habitat Selection” Define the Independent Variable(s) Time in habitat chamber Define the Dependent Variable(s) Type of substrate
Creating an ExD Define the Experimental Group(s) Cut grass, wood chips Define the Control Group Chamber with natural humus substrate
Creating an ExD Make a Hypothesis If Pillbugs prefer the natural humus chamber, then they will stay there at least 80% of the time after the first 10 minutes of experimentation.
Creating an ExD Determine the Experimental Constants Moisture level, temperature, food, lack of predation Choose and Sketch the set-up
Creating an ExD Determine the number of trials or groups needed for validity 10 pillbugs/chamber 10 thirty-second trials Determine how the results will be quantified # of pillbugs/ chamber/30 sec
Write Up the Procedure 1) Prepare a choice chamber 2) Cover the bottom of each chamber with either wood chips, cut grass or natural humus 3) Transfer ten pillbugs from the stock culture into each choice chamber 4) Cover the chambers
Write Up the Procedure 5) Count and record how many pillbugs are in each chamber every 30 seconds for I0 minutes
Run the Experiment Quantitatively summarize data Make a Graph of the number of pillbugs in experimental and control chambers per 30 second interval. Analyze the trend
Analyze The Results Interpret statistics properly DON’T make broad statements from small samples Not: This experiment proves that pillbugs prefer pine needles as a substrate Instead: The results show that pillbugs seem to prefer pine needles as a substrate)
Analyze The Results Compare data with other groups Analyze the trends Address errors Look at all alternative interpretations
Come to a Conclusion Validate the hypothesis Decide whether your data fits your hypothesis or whether you need further testing and revision.
Retest Re-test Peer Review Refine the experiment Example: Choose the same size pillbugs