# Statistical tests and levels of measurement Flashcards

Nominal data

The level of measurement that shows categories of data represented by frequencies. The data sets have no relative numerical value

Ordinal Data

The level of measurement where data can be placed into ascending or descending order, but the intervals between data not necessarily equal e.g. the times for first, second and third in a race.

Interval Data

The level of measurement that has equal numerical intervals between scores, with no absolute/true zero e.g. temperature. The interval between 1 and 2 degrees is the same as between 21 and 22 degrees,

Ratio Data

The level of measurement that has equal intervals between scores and has an absolute or true zero point e.g. speed (mph)

Probability value

A numerical value that gives an indication of the likelihood that results are due to a real difference/correlation and not due to chance e.g. in psychology we accept a probability value of 95%, where results are due to chance in 5% of cases.

Significance level

A numerical value that is usually expressed in value including two decimal places. This level tells you the margin of error that could occur in your results e.g. 0.05 suggests that there is a 5% possibility that results are due to chance and not the difference/correlation between variables.

Observed/Calculated value

The numerical value that is created as a result of inferential statistical analysis of your data. This will be compared to the critical values for the test to calculate the level of significance.

Critical value

The tabulated numerical values that have been assigned to a particular inferential statistical test. It is compared to the observed value for your set of data to calculate significance.