Experimental Design

Question 1

Observational Design

Answer 1

a research technique where you observe participants and phenomena in their most natural settings

Question 2

Experimental Design

Answer 2

the process of carrying out research in an objective and controlled fashion so that precision is maximized and specific conclusions can be drawn regarding a hypothesis statement.

Question 3

Why do you only change one variable?

Answer 3

To make an inference about one factor influencing the other, you want to change only the hypothesized factor between the groups you are comparing and hold all other factors constant

Question 4

Independent/treatment variables

Answer 4

one or more likely casual variables that you can manipulate-> varied in systematic way across experimental units in experimental group

Question 5

experimental group

Answer 5

a group that has been subjected to a hypothesized casual factor

Question 6

control group

Answer 6

a group that has the baseline condition, providing a comparison to experimental group to asses the effect of treatment

Question 7

Potentially confounding variables

Answer 7

other variables that are held constant between groups; factors that could interfere with the experiments outcome

Question 8

Dependent, or outcome, variables

Answer 8

something that depends on other factors.

Question 9

why do we want conclusions to be generalizable

Answer 9

experiments help us uncover potential cause and effect relationships underlying a general pattern

Question 10

Scope of Inference

Answer 10

can we say something about the world in general and not just a specific circumstance

Question 11

Replicates (replicate control/experimental treatments)

Answer 11

• achieved by applying treatment to multiple experimental units: ex. individual student, Petri dish
  
  • what inference do you want to draw → individual, population, or community
• allows you to reduce uncertainty + improve generality of results

Question 12

increase scope of inference → repeat the experiment (why?)

Answer 12

• natural variation = always among experimental unit
  
  • increase confidence in results → assign experimental units randomly to groups if possible → won’t differ by something that could confound results
• using replicates increases the chance that differences you observe among groups/treatments = due to experimental manipulation and not some other confounding factor

Question 13

Hypothesis

Answer 13

proposes an explanation for a pattern → ,ust make clear the evidence that would support/disprove the explanation

Question 14

falsable

Answer 14

should be able to show the hypothesis = wrong through testing