Correlation Co-efficient indicates the strength of a relationship between two variables. It is represented using a number that could range from +1.0 to -1.0
Concurrent Validity results obtained from experiments are prepared from already exsisting results from a widely recognised experiment.
Content Validity is it measuring what it's set out to measure?
Content Analysis an indirect observational technique used to analyse content e.g. documents, messages, verbal content, media material...
Experimental Hypothesis refer to when using an experimental method e.g. lab, field. You use the term Alternative Hypothesis when referring to any other kind.
An Aim is a general statement. A Hypothesis turns an aim into a clear and testable statement with a prediction. When making a hypothesis you have to use Operationalisation: defining the variable so it can be tested. You use a Directional Hypothesis when previous research has already indicated the direction.
Co-variables are variables that have a relationship in a correlation analysis.
Levels of Data
Nominal data is simple frequency headcount in discrete catergories (use the MODE)
Ordinal data can be put into rank order (use the MEDIAN)
Ratio measurements are on a scale which are known and equal. (use the MEAN)
Ratio data has a true zero point e.g. time Interval data can go into negative values
The mode, median and mean are Measures of Central Tendancies. You use the median when extreme values are present.
Measures of Dispersion
- quick and easy to calculate
- doesn't provide info of distrubution of values around the centre
- doesn't take individual values into account so affected by outliers
The Interquartile Range may overcome potential outliers
Standard Deviation is an accurate measurement that is able to measure the likeleness of the data being due to chance. The outliers can skew the curve.
A small scale trial of a study that you plan today to test every aspect of the design with a view to making improvements.
e.g. whether the p's understood the instructions clearly or if there were any extraneous variables.
( a variable other than the IV which can potentially affect the DV)
We can control extraneous variables by
- standardising procedures
- eliminate or keep constant extraneous variables