Experimental and non-experimental correlational studies

Question 1

considerations in causal effects and inference considerations

Answer 1

• establish a cause-effect linkage between specific variables: if X then Y (so changes in A leads to changes in B)
• identify targets that can be controlled or manipulated (changes in outcome)
• internal validity

Question 2

Independent variable / predictor variable / treatment variable

Dependent variable / ultimate / outcome variable

Answer 2

• manipulated by the researcher to see if it affects the DV
• measured to see if affected by IV

Question 3

3 necessary bases for inferring causation

Answer 3

• correlation
• temporal precedence (ordering - so variation in IV should occur before changes in outcome)
• ruling out extraneous factors

Question 4

EXPERIMENT
- mani_ulation
- random_zation
- standar_ization

Answer 4

• deliberately varying the predictor conditions (levels of treatment, control/experimental groups)
• randomly assign ppl to different groups and each one has a different treatment
• formalized procedures, enviro. factors constant, lab setting

Question 5

What are the two EXPERIMENTal design with treatment and control groups?

Answer 5

Independent measures (between subject design): randomly assigned to Condition 1 or Condition 2

Repeat measures (within-subjects design): experience all levels of the IV (their own controls)
+ when few participants are available
+ conduct the experiment more efficiently
- order effects
- fatigue effect / reduced motivation
=> counteract with counterbalancing

Question 6

Disadvantages of a lab EXPERIMENT

Answer 6

• artificiality decreases the ecological and external validity
• decreases generalizability of the results)
• no. of variables manipulated is limited (focus on single IV of interest)

Question 7

Define correlational research

Answer 7

• researcher does not have as much control as they do in an experiment

=> emphasizes ind. differences and effort to establish relationships among those differences on various personality characteristics

Question 8

What do correlational research use?

Answer 8

• statistical measures to establish association or correation

Question 9

CORRELATIONAL
what are the factors shaping the relationships bet. 2 variables?

Answer 9

• reliability (2 variables can only correlate to the extent each measure is reliable)
  => if we use a poor measure of low quality, that decreases the reliability and leads to inaccurate data and correlation
• third variable issue (al. explanations)
  Is A the cause of B or is there C?

-restricted variation of scores (maximize ind. differences)
=> size of correlation bet. 2 variables

Question 10

CORRELATIONAL
Longitudinal studies

Answer 10

• follow the same group over time
• can A predict B?
• measured more than once, measure same variables (ideally)
  *can explore temporal ordering or sequence of these variables

Question 11

CORRELATIONAL
cross-sectional studies

Answer 11

• measured once

Question 12

Types of correlation coefficients
s_nchronous
au_o / te_t-re_est / lag_ed
cro_s-la_ged

Answer 12

synchronous: cross sectional
- correlation bet. X and Y measured at the same point in time

auto: same variable measured at different. times
Variable X measuredat time 1 and variable X measured at time 2

cross-lagged:
- X at time 1 and Y at time 2

Question 13

Mediator vs Moderator variable

Answer 13

Mediator: “accounts” for X and Y relationship

Moderator: different levels of moderator variables show different sizes of the relationship