Sections 1-3 Descriptive vs. Inferential & Scales of Measurement

Question 1

Descriptive vs. Inferential Statistics

Answer 1

DESCRIPTIVE STATISTICS = SUMMARIZE Data (Ex: average, Range)

INFERENTIAL STATISTICS = tools that indicate HOW MUCH CONFIDENCE we can have when generalizing from a sample to a population (Ex: Margin of Error)

Question 2

Population and Census

Answer 2

POPULATION = any group in which a researcher is interested. It may be large, such as all adults age 18 and over who reside in the United States, or it may be small, such as all registered nurses employed by a specific hospital.

CENSUS = A study in which ALL MEMBERS of a population are included. Often, the terms CENSUS and POPULATION will be used interchangeably when referring to working with ALL MEMBERS of the group being studied (instead of a sample)

NOTE: Because a CENSUS can be massive and impractical to work with, researchers often work with SAMPLES, which are a representative portion of the CENSUS

Question 3

Parameters vs. Statistics

Answer 3

Keywords: STATISTICS come form SAMPLES, PARAMETERS come from POPULATIONS (or CENSUS)

PARAMETER = Descriptive tools, such as averages and percentages for CENSUS data

STATISTIC = Descriptive tools, such as averages and percentages for SAMPLE data

Question 4

Scales of Measurement

Answer 4

Memory of Scales: “No Oil In Rivers”

• NOMINAL – Naming Level (Name political parties, tree types, and regions of the USA)
• ORDINAL – puts date IN ORDER from high to low, but it does not specifically indicate how much higher or lower one value is in relation to another.
• INTERVAL – indicate how much the values differ from each other. It is helpful to think of these as the EQUAL DISTANCE levels and NO ABSOLUTE ZERO (Ex: IQ has no absolute zero as a value)
• RATIO – indicate how much the values differ from each other. It is helpful to think of these as the equal distance levels but it DOES HAVE an ABSOLUTE ZERO (Ex: We know where the zero is on a tape measure when measuring distance.)

Question 5

Anecdotal Information

Answer 5

Recognizing patterns using our OWN OBSERVATIONS about the world around us.

Question 6

Scientific Method

Answer 6

The system that scientists use to acquire new knowledge – intended to reduce the likelihood of drawing incorrect conclusions:

Memory: O.H.C.I.C “Observant Hippos Can Interpret Conclusions.”

1. Make OBSERVATIONS about a phenomenon.
2. Create a HYPOTHESIS that might explain the observations.
3. Collect data to CHALLENGE the hypothesis.
4. INTERPRET the data.
5. Draw CONCLUSIONS that state whether the hypothesis held up under scrutiny.

Question 7

Variability

Answer 7

Describes how DIFFERENT the responses are from each other. Are the Scores wide-ranging, or are they all very close to one another?

Question 8

Meaningful Patterns vs. Random Chance

Answer 8

Experiments are used and Statistical analysis is done to determine if patterns exist or not (are random).

Question 9

data vs. datum

Answer 9

Data is the plural of Datum.

Question 10

Average

Answer 10

The performance of a TYPICAL subject.

Question 11

Percentage

Answer 11

a DESCRIPTIVE statistic that describes how many UNITS PER 100 have a certain characteristic.

Ex: if 42% of a group of individuals are Democrats, 42 out of each 100 individuals in the group are Democrats.

Question 12

Sample

Answer 12

A representative portion of an entire Population (or Census) used for statistical study.

Question 13

Margin of Error

Answer 13

An INFERENTIAL Statistic used to warn that sampling from a larger population may produce errors, which should be considered when interpreting results.

Question 14

Nominal (Categorical) Scale of Measurement

Answer 14

NOMINAL – Naming Level (Name political parties, tree types, and regions of the USA) NOT something that has an agreed upon order. So NOT typically in any objective order.

Question 15

Ordinal (Ordered) Scale of Measurement

Answer 15

ORDINAL – puts date IN ORDER from high to low, but it does not specifically indicate how much higher or lower one value is in relation to another.

Question 16

Interval (Distance Between) Scale of Measurement

Answer 16

INTERVAL – indicate how much the values differ from each other. It is helpful to think of these as the EQUAL DISTANCE levels and NO ABSOLUTE ZERO

• Ex: IQ has no absolute zero as a value

Question 17

Ratio (Relative Size) Scale of Measurement

Answer 17

RATIO – indicate how much the values differ from each other. It is helpful to think of these as the equal distance levels but it DOES HAVE an ABSOLUTE ZERO (Ex: We know where the zero is on a tape measure when measuring distance.)