Experiments

Question 1

Explain Extraneous variables and Confounding variables?

Answer 1

Any variable that you are not intentionally studying in your dissertation is an extraneous variable that could threaten the internal validity of your results

When an extraneous variable changes systematically along with the variables that you are studying, this is called a confounding variable. A variable is considered to be confounding because it provides an alternative explanation for your results; that is, an alternative explanation for the relationship or differences between the variables and/or groups that you are measuring. This threatens the internal validity of your results.

Question 2

Explain Multicollinearity?

Answer 2

If two or more explanatory variables are strongly correlated, we cannot identify the individual correlation with the response variable.

Question 3

Explain Between subject experiments?

Answer 3

In a between-subjects experiment, each participant is tested in only one condition.

It is essential in a between-subjects experiment that the researcher assign participants to conditions so that the different groups are, on average, highly similar to each other.

Question 4

What is random assignment?

Answer 4

Random assignment –> using a random process to decide which participants are tested in which conditions
• Do not confuse random assignment with random sampling
o Random sampling is a method for selecting a sample from a population
o Random assignment is a method for assigning participants in a sample to the different conditions

Question 5

What is Within subject experiments?

Answer 5

In a within-subjects experiment, each participant is tested under all conditions
• The primary advantage of this approach is that it provides maximum control of extraneous participant variable

Question 6

Explain Simultaneous within-subjects designs?

Answer 6

There are many ways to determine the order in which the stimuli are presented, but one common way is to generate a different random order for each participant.

Question 7

What could be an extraneous variable in your study?

Answer 7

Situational variables, were the tasks understandable, personal variables (mood, intelligence)
• Alternative explanations for a high intention-score: Mood, distractions, tiredness, personality, comprehensibility of a particular question
• If the extraneous variable occurs systematically throughout the survey it becomes a confounding variable

Question 8

What is Ecological Momentary Assessment?

Answer 8

• Ecological momentary assessment (EMA) involves repeated sampling of subjects’ current behaviors and experiences in real time, in subjects’ natural environments. EMA aims to minimize recall bias, maximize ecological (external) validity, and allow study of microprocesses that influence behavior in real-world contexts.
• Ecological refers to the external validity of the response.
• This can be done automatically by sensors or by notifications sent at prespecified intervals to prompt users to answer questions. This is often more accurate than older data collection methods that require people to recall their behaviour or feelings days, weeks or months later.
• Questions concern current or recent emotions, behaviours or thoughts. These might not be recalled after a week.
• Reporting can focus on:
• Random time periods
• Fixed time periods
• Triggered by events: e.g. purchase of product, use of social media

Question 9

What are the pros and cons with using convenience sampling?

Answer 9

Pros: convenient, cheap, quick. Cons: not a representative sample

Question 10

What could have been an alternative sampling method?

Answer 10

Quota sampling, simple random sampling

Question 11

How could an experiment be used in the context of your research?

Answer 11

• Nudging - 1 treatment group, 1 control group (monetary, convenience etc.)