Lesson 2

Question 1

Independant variable (IV)

Answer 1

variable being manipulated to understand the effect (e.g. type of drink - caffeine / non caffeine drink to measure productivity) - operationalise e.g. 1 cup of coffee with tablet with precise amount - e.g. 100 mg caffeine

Question 2

Dependant variable (DV)

Answer 2

The variable that is being measured or observed in an experiment (e.g. productivity after consuming a caffeine / non caffeine drink) - operationalise e.g. number of words written in a 2h period to write report

Question 3

Independent sample design

Answer 3

participants randomly assigned to different groups (experimental and control groups), measured only ONCE on DV - either before OR after manipulation, no pre-test fo

Question 4

Pre-test / Post-test design

Answer 4

participants randomly assigned to different groups (e.g. experimental and control group), both groups measured on on DV (productivity) twice - once before, once after

Question 5

confounder, confounding variable / factor

Answer 5

create the appearance of a relationship between IV & DV, but there isnt one (e.g. relationship between caffeine intake (IV) and productivity (DV) - confounding var = sleep quality)
other typical: natural history, placebo effect, demand characteristic

Question 6

quasi-experimental design

Answer 6

independent design without random allocation

Question 7

paired samples design / repeated measures / related / within-subjects

Answer 7

all participants complete each condition in the experiment (e.g. each participants is given both caffeine and non-caffeine drink, productivity measured, each participant is their own control group) = compare mean productivity between 2 conditions

Question 8

Counterbalancing

Answer 8

randomly allocating into different orders that they complete the conditions in (e.g. half of the participants receive the caffeine drink first followed by the caffeine drink and the other half does it the other way around)

Question 9

Order effects

Answer 9

influence that the sequence or order of presenting conditions or treatments in an experiment can have on participants’ responses or behavior
main: practice effect and fatigue effect

Question 10

matched pairs design

Answer 10

control for individual differences between participants by pairing them based on relevant characteristics (e.g. 1) select participants that are similar in relevant characteristics that could affect productivity - age, gender, baseline productivity levels, caffeine tolerance etc.
2) pair participants based on characteristic that should be similar as closely as possible
3) randomly assigning one member of each matched pair to the opposite condition = potential differences are not due to individual differnces
4) measure productivity after each consume their assigned drink, then compare productivity score with each matched pair to evaluate effect of treatment