Psychology - data test flashcards

what does standard deviation mean?

how far, on average, scores are different from the mean

What does a large standard deviation indicate?

high variability, greater dispersion, less consistency

What does a small standard deviation indicate?

data more spread around the mean, low variability

what does standard error mean?

how accurate the mean of any given sample from that population is likely to be compared to the true population mean

what does a high standard error indicate?

the mean is an inaccurate representation of the true population mean, less certainty

what does the interquartile range find?

outliers

how do you find Q1 (interquartile range)

find the middle value in the first half (before Q2) of the rank-ordered data set

how do you find Q2 (interquartile range)

find median value in the set

how do you find Q3? (interquartile range)

find the middle value in the 2nd half (after Q2) of the rank-ordered data set

what is the formula for interquartile range?

Q3 - Q1

How do you find high outliers in a set?

Q3 + 1.5 x IQR

How do you find low outliers in a set?

Q1 - 1.5 x IQR

what does a p-value of < 0.05 indicate?

the difference between the means/relationship between the variables is statistically significant

what does a p-value of > 0.05 indicate?

the difference between the means/relationship between the variables is not statistically significant; likely to have happened by random chance; fail to reject null

what is the strength & direction of this relationship - r = -0.5

negative, moderate relationship

what is the strength & direction of this relationship - r = 0.2

positive, weak correlation

what is the strength & direction of this relationship - r = 0.94

positive, significantly strong relationship

what is the strength & direction of this relationship - r = -0.78

negative, strong relationship

what does a positive correlation indicate?

as one variable increases/decreases, so does the other

what does a negative correlation indicate?

as one variable increases, the other decreases

in a correlational study, what does the null hypothesis state?

there is no correlation between the two variables

when do you accept the null hypothesis and reject the alternative hypothesis?

when the p value is more than 0.05

when do you accept the alternative hypothesis and reject the null hypothesis?

when the p value is less than 0.05

the current research had a r value of -0.96 while the previous research had an r value of -0.44. contrast the r value for the current research with that of the previous research.

the correlation coefficient for the current research was stronger than the one from previous research.

say that an experiment was conducted in which females had a SD of 1.19 and males had an SD of 0.64. Distinguish between the SD scores and explain what this reveals about the two groups’ data.

Females had a higher standard deviation (1.19) than males (0.64). This indicates greater variability in the data (/more dispersion) for females compared to males.