Correlations + types of data

Strengths of correlation:

Provide a precise quantifiable measure of how the two variables relate.

Correlations are a good start for experiments to predict what outcome there will be.

Quick and economical.

Weaknesses of correlation:

Can tell us how variables relate but not why.

Cannot create cause-effect relationship between variables.

May be a third variable causing the effect.

Qualitative data:

Non-numerical data.

Pro - more detail, greater external validity

Con - difficult to analyse, subjective

Quantitative data:

Numerical data.

Pro - easy to analyse, objective

Con - less detail, not representative

Primary data:

Information obtained first-hand by the observer.

Pro - fits the investigation

Con - high time, effort and money

Secondary data:

Information obtained second-hand by another researcher.

Pro - low time, effort and money

Con - variation of quality, accuracy and relation