1. Introduction to Experimental Design
Histograms, Variables, and Analysis

2. Bellringer
Create a frequency table and Histogram using the given information.
Write down the frequency table and draw the histogram on your paper.
Test scores for a high school Biology Test
Range 
Frequency
70 – 79 81 77 63 92 97 68 72 88 78 96 85 70 66 95 80 99 58 83 93 75 89 94 76 90 87
Note: Frequency is how many fit into each number range.

3. What is a histogram? https://www.mathsisfun.com/data/histograms .html
A histogram is a type of bar graph.
But instead of making a bar for every number, you group your data into ranges.
.html

4. Hypothesis Practice Make an if/then hypothesis from the following:
How does the type of shoe I wear (high-heels, tennis shoes, flip flops) affect how high I can jump?
How does the number of pieces of gum I chew (1, 3, 5) affect how big of a bubble I can blow?
How does the amount of water you give to a plant each day (no water, 1 spoonful, 1 cup) affect how tall the plant will grow after 3 weeks?

5. Independent vs. Dependent Variables
Independent variable – the variable varied or manipulated by the experimenter
Dependent variable – the response that is measured
The independent variable is the presumed cause and the dependent variable is the presumed effect.

6. A note on controls
Control – the factors in an experiment that you keep the same
Only one variable in an experiment
Control Group – a group that you do not conduct the experiment on to see if your variable is effecting the results

7. Variables Practice #1
Students watched a cartoon either alone or with others and then rated how funny they found the cartoon to be.
Independent Variable:
Dependent Variable:

8. Variables Practice #2
A comprehension test was given to students after they had studied textbook material either in silence or with the television turned on. Independent Variable: Dependent Variable:

9. Variable Practice #3
Some elementary school teachers were told that a child’s parents were college graduates, and other teachers were told that the child’s parents had not finished high school; they then rated the child’s academic potential.
Independent Variable:
Dependent Variable:

10. Variable Practice #4
Workers at a company were assigned to one of two conditions: One group completed a stress management training program; another group of workers did not participate in the training. The number of sick days taken by these workers was examined for the two subsequent months.
Independent Variable:
Dependent Variable:

11. Variable Practice #5
Students at a University were split into two groups and each received a different text for a philosophy course. Once group received a traditional text book, while the other received an interactive textbook on a tablet computer. After the course, the final exam marks between the two groups of students was compared. Independent Variable: Dependent Variable:

12. Variable Practice #6
Try and design an experiment from the following claims.
 If people spend more time using social media, then they will be less able to express themselves in conversation.
Experiment:
______________________________________________________________________________________________
Independent Variable:
Dependent Variable:

13. Variable Practice #7
Claim: Drinking energy drinks makes people more aggressive. Experiment: __________________________________________________________________________ Independent Variable: Dependent Variable:

14. Variable Practice #8
Taking a nap in the afternoon makes people more relaxed and less irritable for the rest of the day.  
Experiment:
__________________________________________________________________________________
Independent Variable:
Dependent Variable:

15. Variable Practice #9
Spending time with a cat or dog decreases the amount of stress someone is feeling and allows them to perform better on tests.
Experiment:
____________________________________________________________________________________________
Independent Variable:
Dependent Variable:

16. Variable Practice #10
Eating breakfast in the morning increases the ability to learn in school. Experiment: ___________________________________________________________________________ Independent Variable: Dependent Variable: