correlations

Question 1

whats a correlations

give me one strengths and weakness of correlation

Answer 1

1) A measure of how strongly two or more co-variables are related to each other

Strengths:

1. Provides information on the degree of a relationship in the correlation coefficient
2. Provides quantitative data
3. No manipulation of behaviour is needed
4. Suggest ideas for experiments
5. Data may already have been collected, so little time and effort is involved

Weaknesses

1. No cause and effect can be inferred but it often is
2. Other factors affecting the correlation might not be noted by researcher, but may influence variables Extraneous variables

Question 2

whats mean and give strengths and weakness

Answer 2

Adds values, divide by number of values

. We use the mean as it uses all data and when the data is not massively skewed.

strengths
• Makes use of all available data
• The most powerful measure if central tendency.

weakness
• Not suitable for use on data sets with extreme values
• Can only be used on interval or ratio data – not usually suitable for ordinal data.

Question 3

whats median and give strengths and weakness

Answer 3

Middle value in an ordered list

strengths
• Relatively unaffected by extreme scores
• Can be used on data with skewed distributions
• Can be used on ordinal and interval data

weakness
• Does not work well with small data sets.
• Can give a misleading impression if scores are clustered in high and low groups
• Can be affected by any alteration in the central values

Question 4

whats mode and s + w

Answer 4

Most frequently occurring value

strengths
• Easy to calculate
• Only measure that can be used for nominal data (i.e. categories of behaviour)

weakness
• Tells us nothing about other scores in the set
• Often more than one mode in a set of scores so this limits its value

Question 5

whats range

Answer 5

highest minus the lowest

☺Easy to calculate
☹Affected by extreme values