Quantitative Research

Types of experiments

True experiment– Has a control group

Quasi-experiment– No control group– Normal style for work in social sciences since

the independent variables often cannot be adjusted by the experimenter.

Measuring effect

Normal goal of a quantitative study is to measure how a dependent variable changes when the independent variables change.

Independent variable

Variables which can be controlled by the experimenter or are used as the measured in the situation (for example, reading ability or class attendance)

Beware of trying to vary multiple independent variables at once. Interactions between them will cause problems with the data analysis.

Dependent variable

The measured value of interest which changes as the experiment progresses.

The study may require collecting data on multiple dependent variables. They often interact and can hide important effects.

Hypothesis

Write up the hypothesis in terms of both independent and dependent variables. Be specific, so it leads to the data analysis methods.

Hypothesis sample H1: Participants would exhibit more errors when searching for information

on the small-screen display than when searching the full-size display. H2: Participants would exhibit more confidence in answer found when

searching for information on the full-size display than when searching the small-screen display.

H3: Participants would take more time to perform the same tasks when searching on the small-screen display than when searching the full-size display.

H4: Overall, participants would experience more difficulty locating information in the middle and end of web pages than at the beginning. This finding would be more extreme in the small-screen condition.

H5: Overall, participants would experience more difficulty locating text information within a body of text than they would numerical information within a

body of text.

Participants

Group types– Random sample– Stratified random sample– Convenience sample

In the write up, define who they are, how recruited, why recruited, etc.

Procedure

Draw the entire set of measures Multiple conditions can require lots of

people very fast

Procedure for participant groups

Within subjects– Measures before and after with same people– Measure ability, test, remeasure ability

Between subjects– Measures different people– Each person only gets one measurement or test, not

all tests. Repeated measures

– Same person at different times/conditions

Order effects

Order of which a person performs tasks can effect later work.

Alternate between or randomize the order in which people perform the tasks. Then analyze the different orders to show there is not effect on the dependent variable.

End