Chapter 7 assumptions part 1

Meeting the assumptions improves the quality of research, but not meeting the assumptions doesn't necessarily _____ _______.

invalidate research

When we calculate a parametric statistic, ideally we have met assumptions regarding the ____ _____.

population distribution

For a z test, there are ____ assumptions:

3

how many assumptions are there

3

define robust:

A term given to a hypothesis test that produces fairly accurate results even when the data suggest that the population might not meet some of the assumptions.

define parametric test:

An inferential statistical analysis based on a set of assumptions about the population.

define nonparametric test:

An inferential statistical analysis that is NOT BASED on a set of assumptions about the population.

Assumption 1:

DV is assessed using a scale measure only. If the Dv is nominal or ordinal, we could NOT make this first assumption and thus should NOT use a parametric hypothesis test.

the Z test assumption 1 should be

The dependent variable should be on a scale measure,

Assumption 3:

The distribution of the population of interest must be approximately normal. Because hypothesis tests deal with sample means rather than individual scores, as long as the sample size is at least 30 it is likely that this third assumption is met.

Assumption 2:

The participants are randomly selected. Every member of the population of interest must have had an equal chance of being selected for the study.

define assumptions

are the characteristics that we ideally require the population from which we are sampling to have so that we can make accurate inferences.

Many parametric hypothesis tests can be conducted even if some of the assumptions are not ------

met

z test assumption 2 should be

the sample should be randomly selected

z test assumption 3 should be

the underlying population should have an approximately normal distribution 30 or more

assumption 2 is often violated; it is more likely that participants are a convenience sample. If we violate this second assumption, we must be cautious when generalizing from a sample to the population. true or false

true