levels of measurement

What are the 3 levels of measurements and what is the order of it being basic to not

Nominal (most basic)

Ordinal

Interval (least basic)

What is nominal data and what test is it used by and what measures of central tendency can it measure

Nominal - quantities or frequencies

Used by CHI square and SIGN test

Lowest level of information

Because it just a count/ quantity/ frequency

Can’t calculate mean or median of nominal data

Why cant u calculate the median or mean of nominal dat a

Non=minal data is complete categorical and ha no inheriting numerical value

Median means the numbers need to be ranked but u cant say brown eye colour is less than blue - doesn’t make sense

Mean is calculating the averag but the data is usually in different categories so it doesn’t mean anything

ONLY CA;CULATE MODE - WHICH SET HAS MOST

Ordinal data

What tests is it used for

Items in an order where we know place of item that it came in

Gives more info than nominal

Used with MANN WHITNEY u and WILLCOXON T and SPEARMANS RHO

WHAT measures of central tendency can ordinal data tell and not tell

Can tell

Median

Mode

Cant tell mean as the mean requires numerical distance between the numbers to find an average but ordinal is just ranking (eg 5th place)

Interval data

What tests are used with it?

What measures of central tendency is used?

Any data measured using an interval scale

E.g mm metres and millimetres or time in seconds

This test used for PEARSONS R , RELATED T TEST ,, UNRELATED T TEST

What is interval data measure in central tendcy

The interval data can e multiplied and divided

Contains more info than ordinal and nominal

Can calculate ALL 3

What is similar to interval?

Ratio

E.f measuring someting in seconds

Why cants p is 0.1 be accepted

It means 1 in 10 results are due t chance

It’s too high

What do inferential tests check for

If sample is trustworthy to then see if it is significant

It tells us about the sample and therefore the target population and if the sample represents the population