1S Descriptive and Inferential Stat

Question 1

What are descriptive statistics used for?

Answer 1

Descriptive statistics are used to describe the basic features of the data in a study.

Question 2

what are inferential statistics used for?

Answer 2

trying to reach conclusions that extend beyond the immediate data alone OR we use inferential statistics to make inferences from our data to more general conditions

Question 3

What are descriptive statistics useful for?

Answer 3

Descriptive statistics help us to simplify large amounts of data in a sensible way. Each descriptive statistic reduces lots of data into a simpler summary.

Question 4

What is Univariate analysis?

Answer 4

Univariate analysis is a form of analysis that only involves a single variable/ involves the examination across cases of one variable at a time

Question 5

What is Univariate analysis part of?

Answer 5

descriptive statistics

Question 6

Name major characteristics of a single variable

Answer 6

• the distribution
• the central tendency
• the dispersion

Question 7

What is the distribution?

Answer 7

The distribution is a summary of the frequency of individual values or ranges of values for a variable.

Question 8

What would list the simplest distribution?

Answer 8

The simplest distribution would list every value of a variable and the number of persons who had each value.

Question 9

Name one of the most common ways to describe a single variable

Answer 9

One of the most common ways to describe a single variable is with a frequency distribution.

Question 10

What are frequency distributions?

Answer 10

they are visual displays that organize and present frequency counts so that the information can be interpreted more easily

Question 11

How frequency distributions can be depicted?

Answer 11

Frequency distributions can be depicted in two ways, as a table or as a graph. Distributions may also be displayed using percentages.

Question 12

What is central tendency?

Answer 12

The central tendency of a distribution is an estimate of the “center” of a distribution of values.

Question 13

Name major types of estimates of central tendency

Answer 13

• Mean
• Median
• Mode

Question 14

What is dispersion?

Answer 14

Dispersion refers to the spread of the values around the central tendency.

Question 15

Name two common measures of dispersion

Answer 15

There are two common measures of dispersion, the range and the standard deviation.

Question 16

What is the range? Give an example

Answer 16

The range is simply the highest value minus the lowest value. In our example distribution, the high value is 36 and the low is 15, so the range is 36 - 15 = 21.

Question 17

What is the disadvantage of the range?

Answer 17

An outlier can greatly exaggerate the range

Question 18

What does the standard Deviation shows?

Answer 18

The Standard Deviation shows the relation that set of scores has to the mean of the sample.

Question 19

How to compute the standard deviation?

Answer 19

To compute the standard deviation, we first (1) find the distance between each value and the mean.
Notice that values that are below the mean have negative discrepancies and values above it have positive ones.
(2) Next, we square each discrepancy: take these “squares” and sum them to get the Sum of Squares (SS) value.
(3) Next, we divide this sum by the number of scores minus 1. This value is known as the variance. To get the standard deviation, we take the square root of the variance (remember that we squared the deviations earlier).

Question 20

Describe the standard deviation

Answer 20

the square root of the sum of the squared deviations from the mean divided by the number of scores minus one

Question 21

Formula of the standard deviation

Answer 21

check “1S Self study Descriptive Statistics” file

Question 22

When is one of the simplest inferential tests used?

Answer 22

Perhaps one of the simplest inferential test is used when you want to compare the average performance of two groups on a single measure to see if there is a difference