Lecture 3 - Participants

Question 1

What do we need to do when recruiting to ensure results apply to people other than those recruited (results are generalisable).

Answer 1

• recruit people from the population we want to investigate (i.e. should be representative of population)
• recuirt a sufficient number of participants

Question 2

What is the ideal way of sampling a population to get your participants?

Answer 2

Choosing randomly from population.

Question 3

What happens in practice when getting participants?

Answer 3

Conveniance sampling

Question 4

How many people should we recruit?

Answer 4

More is better typically , however it needs to be a feasible number.

We need to consider practical (time to recruit , population difficult to access) and ethical considerations (study puts burden on participants , delays).

Question 5

What is central theorem?

Answer 5

As sample size increase to >= 30 the data becomes approximately normally distributed.

Question 6

What does the central limit tell us?

Answer 6

This means that, if you are measuring abilities that are normally
distributed in general population (e.g. typing accuracy on a task)
then after around 30 people are recruited this will be reflected in
the data.

Question 7

What is a within-subject?

Answer 7

participants do all tasks (all levels) , so we can compare across all

Question 8

What is a between-subject?

Answer 8

A participant that is part of a group completing only a subset of all tasks. We compare performance acorss groups.

Question 9

Which type of a subject is favoured?

Answer 9

The within-subject.

Question 10

left on order effects