PSYC1040 Week 3

Question 1

Basic deisgns - confounds and control techniques

Answer 1

• all studies are vulnerable to confounds, so should include control techniques
• a CONFOUND is typically a specific variable, other than the supposed causal variable of interest, that presents an alternative explanation for important results
• a CONTROL TECHNIQUE is any method used to control the states or influence of variables especially variables not of interest in the study (extraneous variables).
• such variables include confounds but also other problematic variables

Question 2

Both kinds of experiments, done naively, can be confounded

Answer 2

• between groups example: forming groups non-randomly can cause participant characteristics to differ between groups in a way that could explain the results
• addressed by randomly assigning participants to groups
• within groups example: running conditions (treatments) in a consistent order can cause order effects that might explain the results
• addressed by order counter balancing

Question 3

Constructs, operations and variables:
How can we tell when someone is in a good mood?

Answer 3

• they tell us
• laughing
• activity level, talkativeness
• facial expression, body language
• talking about positive things

Question 4

Constructs, operations and variables:

Answer 4

• we judge or guess their mood positively (a construct) based on the states of observable things (variables).
• to get to the states of variables, we use procedures and tools (operations)

Question 5

Constructs, operations and variables: construct

Answer 5

• a concept of something of interest in our study (may/not actually exist)
• not directly observable; its state is uncertain and must be judged from variables

Question 6

Constructs, operations and variables: operation

Answer 6

• usually a method of changing or assessing the state of a construct

Question 7

Constructs, operations and variables: variable

Answer 7

• the score or label produced by an operation
• known with certainty by how well it reflects any construct must be assessed

Question 8

two kinds of operation

Answer 8

manipulations - operations to change the state of a construct
e.g training to change problem - solving technique-procedures to force smoking or non-smoking
Measures - operations to change the state of a construct
e.g interview about problem solving technique - daily log of smoking time

Question 9

Scale of measurement: nominal scale

Answer 9

• names of variables state
• e.g days of year…labelled with season

Question 10

Scale of measurement: ordinal

Answer 10

• +ranking (order
• …ranked by temperature

Question 11

Scale of measurement: interval

Answer 11

• +distance between states
• e.g … labelled with temperature in degrees

Question 12

Scale of measurement: ratio

Answer 12

• • proportion distance from a true zero
• e.g with temperature in Kelvin

Question 13

Extraneous variables (nuisance)

Answer 13

• variables which are not being manipulated or measured but have in some way contributed to the obtained results