Chapter 2: Ways of Displaying and Interpreting Data to Understanding the Meaning of the Data:

Question 1

Descriptive statistics:

Answer 1

Brief summary statements capturing essential information to better understand the meaning of the data.

Main instruments: central tendency and variability.

Question 2

Descriptive statistics: Central tendency:

Answer 2

Descriptions about the meaning of the central tendency measurements.

Question 3

Descriptive statistics: Central tendency: Mean

Answer 3

Average (sum/n)

Question 4

Descriptive statistics: Central tendency: Median

Answer 4

The middle value (after they are arranged from small to big).

Question 5

Descriptive statistics: Central tendency: Mode

Answer 5

Most frequent observation (there can be none).

M[ost]O[bserved]DE

Question 6

Descriptive statistics: Central tendency: Outliers

Answer 6

Odd observation(s).

Question 7

Descriptive statistics: Variability:

Answer 7

Description of how much measurements differ from one another and the meaning of it.

Question 8

Descriptive statistics: Variability: Range:

Answer 8

Difference between the max value and the min value

[max-min = range].

Question 9

Descriptive statistics: Variability: Standard deviation:

Answer 9

The average of the dispersion of the measurements from the mean.

Sample Question: A group of children have a mean height of 150 cm, standard deviation 10. The tallest child is 180cm tall.
The tallest child is 3 SD from the mean.

Question 10

Inferential statistics:

Answer 10

To assess whether differences in our sampled data are likely to be meaningful or if they just happened by chance (no meaning).

Question 11

Inferential statistics: number of people in the sample:

Answer 11

More people reduce the likelihood that our sample is uncharacteristic of the population.

More people increases the likelihood that the data is meaningful/ representative of the population.

Question 12

Inferential statistics: variability between each group:

Answer 12

Bigger differences between groups may reflect a stronger effect of your manipulation.

Question 13

Inferential statistics: Variability within each group:

Answer 13

High variability (differences) within a group reduces potential differences between groups.

Question 14

Inferential statistics: Making a statistical inference:

Answer 14

A paper is willing to accept a 5% or less likelihood that the results are a product of chance.

Question 15

Frequency distribution:

Answer 15

A graphic representation of data/ showing the number of times that a property takes on each value.

Question 16

Frequency distribution: Normal Distribution:

Answer 16

The frequency of measurements for a property is the highest in the middle of the frequency distribution and decreases symmetrically in both directions (usually hypothetical).

The 3 measures of central tendency are the same (mean, median and mode).

Also called: Bell curve and Gaussian distribution.

The value in the middle is observed the most.

Question 17

Frequency distribution: Positive skew:

Answer 17

Data goes more to the left. Mode, median and mean are different.

Question 18

Frequency distribution: Negative skew:

Answer 18

Data goes more to the right. Mean, median and mode are different.