Data Handling and analysis

Quantitative data

Data which holds numerical value, low validity, high reliability. Questionnaires

Qualitative data

Data which is descriptive, high validity, low reliability. Interviews

Primary data

Data which is collected by someone firsthand

Secondary data

Data which has been collected by others.

Meta-analysis

a "study of studies" that combines the findings of multiple studies to arrive at a conclusion - therefore uses secondary data

Measures of central tendency

Mean, median, mode.

Mean

Sum of values divided by number of values

Median

the middle value in a distribution; half the values are above it and half are below it

Mode

Most frequently occurring value in distributions

Measures of dispersion

Range and standard deviation

Range

Distance between highest and lowest values in a set of data.

Calculate %

a/b x100

Positive correlation

A correlation where as one variable increases, the other also increases, or as one decreases so does the other. Both variables move in the same direction.

Negative correlation

the relationship between two variables in which one variable increases as the other variable decreases. They go in opposite directions

Zero correlations

where there is no relationship between variables

Displaying quantitative data

Graphs, tables, scattergrams, bar charts, histograms

Distributions

Normal and skewed

Normal distribution

Bell shaped curve - mean, median and mode are all the same value.

Skewed distribution

When the central measures of tendency are not the same value. leads to positively skewed (graph peaks left) and negatively skewed (graph peaks right) distributions.

Correlation coefficient

a measure of the relationship between two things (from -1 to +1)

levels of measurement

• nominal

• ordinal

• interval

nominal data

Categorical data without a specific order.

ordinal data

a type of data that refers to a ranking.

interval data

Data that is ordered within a range and with each data point being an equal interval apart. e.g time

Content analysis and coding

Transforming content (qualitative data) to quantitative data through coding (assigning categories) to the data set.

Thematic analysis

A qualitative approach to analysis that involves identifying implicit or explicit ideas within the data. Themes will often emerge once the data has been coded.