Module 1/2: Lecture Notes

Question 1

Parameters

Answer 1

A population parameter is a numerical value that describes a characteristic of a population. For example, the population mean height of all students in a school is a population parameter.

Question 2

Statistics

Answer 2

Numerical description of a sample characteristic

Question 3

What is the difference between a parameter and a statistic?

Answer 3

The difference between a parameter vs a statistic is that a parameter is a fixed measure describing the whole population, while a statistic is a characteristic of a sample, a portion of the target population.

Question 4

Descriptive statistics (3)

What it is+ what it does+ ex

Answer 4

• The organization, summarization and display of data
• simplifies data to make large groups of numbers easier to grasp
• Ex: Did you go away for break? -> ask everyone and find the amount that stayed and went away. -> use % to summarize

Question 5

Inferential statistics (3)

What it does+ generalize+ draw conclusion

Answer 5

• Draw conclusions about a population based on data from a sample
• Generalize about a characteristic we cannot measure directly
• Enable researchers to draw conclusions when it might be impossible to measure all members of the population of interest

Question 6

Discrete data is

Answer 6

categorical

Question 7

Quantitative Data (2)

What it is+how is it presented?

Answer 7

• Information about quantities; How much or how many of something
• Presented as a set of numbers

Question 8

Continous Data

Answer 8

Take on any value in some interval and are not restricted to any list of values value in some interval

Question 9

Discrete data

Answer 9

Can be listed

Question 10

What level of measurement is continous?

Answer 10

Ratio, Interval

Question 11

Which level of measurement can quantify the difference between values?

Answer 11

Interval, Ratio

Question 12

Which level of measurement can add/subtract?

Answer 12

interval/ratio

Question 13

Which level of measurement can multiply/divide?

Answer 13

ratio

Question 14

Which level of measurement has inherent true values?

Answer 14

ratio

Question 15

Variables(3)

What it is+ can be…

Answer 15

• Something that varies
• Can be a few levels (ex: 2-4 for categorical, left or right handed)
• Can have many values (Continous data)

Question 16

Experimental Study (2)

What it is+ what researchers do

Answer 16

• A treatment, proedure or program is intentionally introduced and a result or outcome is observed
• Researchers compares outcomes between those who received treatment and those who did not

Question 17

Independent variable

Answer 17

Actively manipulated

Question 18

Dependent Variable

Answer 18

Changes as a result of manipulation of IV

Question 19

Confounding variables

What it is+ varies with + impossible to…

Answer 19

• Anything that could cause change in B that is not A
• varies with the IV
• Impossible to identify the cause of any change in the DV

Question 20

Validity

Answer 20

Does the experiment measure what it is intended to measure

Question 21

Reliability

Answer 21

refers to how consistently a method measures something

Question 22

Frequency Tables

Answer 22

Shows discrete data values along with frequency of each

Question 23

Unimodal

Answer 23

One highest frequency or value

Question 24

Skewed distributions

Answer 24

Have many more scores on one side of a distribution than on the other side

Question 25

Negative skew

Answer 25

Left tail is longer

Question 26

Positive skew

Answer 26

Right tail is longer

Question 27

Way to measure central tendency (3)

Answer 27

Mean
Mode
Median

Question 28

Mean

Answer 28

A set of scores is the sum of the scores divided by the number of scores

Question 29

Median

Answer 29

The midpoint

Question 30

Mode

Answer 30

The value that occurs the most often. It also represents the highest peak or column in a graphed frequency distribution.

Question 31

Central tendacy of positive skew

Answer 31

Question 32

Central Tendency of Negative Skew

Answer 32

Question 33

Population mean

Answer 33

Question 34

Sample Mean

Answer 34

Question 35

Deviation

Answer 35

The distance of a score x from the mean of the distribution it is included in

Question 36

Deviation of the entire population

Answer 36

(x-μ)
distance between data point x and the population mean

Question 37

Deviation of sample

Answer 37

(x-X̄)
distance between a point x and the sample mean x-bar

Question 38

Why do we square deviance rather then absolute it?

Answer 38

Because you dont want to underplay any outliers

Question 39

When a sample variance is calculated, the sum of the values is divided by n-1 instead of n. This is done to —–

Answer 39

correct for the tendency of the sample variance to slightly underestimate the population variance

Question 40

Population standard deviation symbol

Answer 40

σ
sigma

Question 41

Sample standard deviation symbol

Answer 41

s

Question 42

What is standard deviation?

Answer 42

It is a measure of the variability within a distribution

Question 43

A data point that is several standard deviation from the mean may be ….

Answer 43

just due to random variation but it could also signify an unsual event that needs to be investigated

Question 44

What do Z scores do?

Answer 44

Gives the distance in standard deviations from a data point to the mean of the distribution it is included in

Question 45

How are Z scores calculated?

Answer 45

Question 46

Multiplying the z-score by the standard deviation tells us—– adding that to the mean gives—–

Answer 46

• how far the raw data value is from the mean in terms of the original data values
• the exact location or data point

Question 47

Qualitative data

Presented as

Answer 47

presented as names or categories