Experimental Design Student Cheat Sheet 2017 Variables Independent

Experimental Design Student Cheat Sheet 2017

Variables • Independent variable (IV): the variable that is purposely changed in an experiment. • Dependent variable (DV): the variable that responds to the change (IV). It is measured or observed.

IV groups • Different types of IVs that are used – Ex. Type of Vitamin • IV Groups: Vitamin K, Vitamin A, Vitamin C Always include UNITS on IV or DV if needed

Constants • Things that are kept the same in an experiment. Everything besides the IV must be kept constant for the experiment to be valid. • It’s important to keep all other variables constant so the experimenter knows what is causing the DV to change.

Control • The group that is used as a standard of comparison in an experiment. The control may be “no treatment” or “experimenter selected” It allows you to know if the IV truly affected the DV.

Experimental Question • A question which deals with how the IV will affect the DV. • How does the ______(IV) affect the _______ (DV)? • Don’t forget the Question Mark!

Hypothesis • A prediction made about a possible outcome of an experiment • It must be testable and based on previous knowledge • It is a statement that includes the IV and DV. • Must include: If … then • Must be specific! (Pick an IV group and DV change)

Data Table • Must have TITLE at the top including the IV and DV: The effect of _____ (IV) on the ______ (DV). • IV: left column- include units • DV: top middle- include units • Trials- top • Average- right column

Title: include the IV and DV DV: IV: Trial 1 Trial 2 Trial 3 Trial 4 Average

Graphs • Must have title at the top- the same as the title on data table • X-axis- IV (units) • Y-axis- DV (units) • Half Rule- Use most of the graph paper • Graph only the Averages! • Include labels or keys for multiple lines or bars • Use appropriate scale on each axis

Bar graph or line graph? • Line graph: data is related and continuous ex. Time or Temperature • Bar graph: data is unrelated categories or discontinuous ex. Honda, Ford, Chevy

Conclusion 1. Purpose of the lab- restate the experimental question 2. Data- report major findings- put data table into words using averages 3. Hypothesis – state it and tell if it was “supported” or “not supported” by the data 4. Patterns in the data (look at graph) 5. Recommendations for improvements (Players Don’t Hate Players Rock!)