Univariate Data

bivariate correlations

relationships between 2 distributions of scores

If we sampled the entire population, in theory what kind of distribution would we get?

normal distribution

Most people are __ which is why we see more scores in the center of the x axis

average

What is central tendency?

the tendency of the measures to fall in the center of the distribution

What is the mean?

average score

2 multiple choice options

outliers pull the mean ___ them

towards

1 multiple choice option

What is the median?

middle score

1 multiple choice option

What are outliers?

extreme scores that may skew or flatten distributions of scores so that the distribution is no longer normal

extreme scores ___ distributions of scores

skew or flatten

1 multiple choice option

with platykurtic scores, the SD is

higher

1 multiple choice option

with leptokurtic scores the SD is

lower

1 multiple choice option

This is an example of a leptokurtic distribution

This is an example of a platykurtic distribution

which axis is the frequency of scores on?

y axis

What axis is the outcome measure on?

x axis

symmetrical scores have ___ means and median

equal

1 multiple choice option

This is an example of a negatively skewed distribution

what happens to the mean with negatively skewed distributions

pulled left

1 multiple choice option

if the mean is < the median the distribution is skewed

negatively

1 multiple choice option

lots of scores on the high end of the scale

ceiling effect and negative skew

3 multiple choice options

This is an example of a positively skewed distribution

with positively skewed distributions, which way is the mean pulled?

to the right

when there is a high number of low scores

floor effect and positive skew

3 multiple choice options

with positive skewed distributions, the mean is pulled towards abnormally __ scores

high

1 multiple choice option

with negatively skewed deviations, the mean is pulled towards abnormally __ scores

low

1 multiple choice option

what is the range?

distance between minimum and maximum scores

what is the standard deviation?

average variation of each score from the mean

How many SD away from the mean is an outlier?

more than 3 standard deviations

95% of scores is how many SD from the mean?

2 SD

2 multiple choice options

What is a z score?

the number of standard deviations from the mean at which a score is located

What do z scores tell us?

where a particular score is located on a distribution

how do you calculate the Z score from a pts outcome measure results?

Take their score, and subtract the mean. Then divide that by the SD

For a confidence interval to be more confident, it needs to be

Wide

1 multiple choice option

For a confidence interval to be more precise, it needs to be

Narrow

1 multiple choice option

What does a 95% confidence interval mean?

95% confident that the true population mean falls within the range of CI

What does the standard error of the mean tell us

how closely we can estimate the population mean from our sample mean and standard deviation

As sample size increases, what happens to standard error of the mean

SEM decreases

2 multiple choice options

how are sample size and SEM related

inversely

1 multiple choice option

which will always be higher, SD or SEM?

SD

1 multiple choice option

what is the formula for high end of 95% confidence interval

mean + (1.96x SEM)

what is the formula for the low end of 95% confidence interval

mean - (1.96 x SEM)

Large error bars mean SD is

large

Large error bar means spread of scores is

large

1 multiple choice option

What is an error bar

one SEM above ad one below the mean of the sample

When can parametric statistics be run

when data is "fairly normally" distributed

T/F variability is always bad

false

Can we use parametric statistics on skewed data

no

1 multiple choice option