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Question 1

What is a population?

Answer 1

An entire group of individuals or objects that you want to study

Populations can vary in size and characteristics depending on the research focus.

Question 2

What is a sample?

Answer 2

A smaller, more manageable group selected from the population to represent the larger group

Samples are essential for conducting research when studying an entire population is impractical.

Question 3

Define parameter.

Answer 3

A numerical value describing an entire population’s characteristics

Parameters are often unknown and must be estimated using statistics from samples.

Question 4

What is a statistic?

Answer 4

A numerical value that describes a characteristic of a sample

Statistics are used to infer about the population parameters.

Question 5

What are individuals in the context of data?

Answer 5

Persons or objects described by a set of data

Individuals can include anything from people to items in a study.

Question 6

What are variables?

Answer 6

Characteristics or measurements that we are interested in studying

Variables can vary between individuals or over time.

Question 7

Define quantitative variables.

Answer 7

Numerical measurements, such as age, height, weight, or income

Quantitative variables can be discrete or continuous.

Question 8

What are categorical variables?

Answer 8

Categories or labels, such as hair color, occupation, or favorite type of food

Categorical variables can be nominal or ordinal.

Question 9

What is data?

Answer 9

Actual values of the variables (raw information) that we collect and analyze to gain insights into the phenomenon we are studying

Data can be qualitative or quantitative.

Question 10

What is random sampling?

Answer 10

Process that allows researchers to choose a random set of individuals from a population

Random sampling helps to avoid bias in research.

Question 11

Define simple random sample.

Answer 11

Sample chosen from a population from which each possible subset of the same size has an equal probability of being chosen

This method ensures that every individual has an equal chance of selection.

Question 12

What is stratified sampling?

Answer 12

Method of random sampling that involves dividing the population into distinct subgroups called strata, based on specific characteristics such as age, gender, or socioeconomic status

Stratified sampling ensures representation across key characteristics.

Question 13

Define cluster sampling.

Answer 13

Method of random sampling that involves dividing the population into clusters, which are naturally occurring groups like schools, neighborhoods, or cities

Clusters are then randomly selected for study.

Question 14

What is systematic sampling?

Answer 14

Method of random sampling that involves selecting every nth individual from a list of the population, starting from a randomly chosen point

Systematic sampling can be easier to implement than simple random sampling.

Question 15

Define explanatory variable.

Answer 15

Variable that a researcher manipulates or observes changes in to explain or predict the results

Explanatory variables are also known as independent variables.

Question 16

What is a response variable?

Answer 16

Variable that represents the outcome the researcher is interested in explaining or predicting

Response variables are also known as dependent variables.

Question 17

What is an observational study?

Answer 17

When researchers observe and record data on variables as they naturally occur, without any intervention or manipulation

These studies can show correlations but not causation.

Question 18

Define sample survey.

Answer 18

Specific type of observational study where individuals self-report the values of variables, often by providing their opinions or answering questions

Surveys can be affected by response bias.

Question 19

What is an experiment?

Answer 19

When researchers intentionally manipulate one or more variables (the explanatory variables) to observe their effect on another variable (the response variable)

Experiments are designed to establish cause-and-effect relationships.

Question 20

What are treatments in an experiment?

Answer 20

Different values of the explanatory variable

Treatments are applied to experimental units to observe effects.

Question 21

Define experimental unit.

Answer 21

A single object or individual being measured

The experimental unit is the smallest entity to which a treatment is applied.

Question 22

What is randomization in research?

Answer 22

When objects or individuals are randomly assigned (by chance) to an experimental group

Randomization helps to eliminate bias and ensures comparability.

Question 23

Define replication in research.

Answer 23

When the experiment is repeated with a sufficiently large sample size, or reproducing the entire study to confirm previous findings

Replication enhances the reliability of research results.

Question 24

What is a control group?

Answer 24

Group of participants in an experiment who do not receive the experimental treatment

Control groups are essential for comparison against treatment groups.

Question 25

Define placebo.

Answer 25

Inactive treatment that has no real effect on the response variable ## Footnote Placebos are often used in clinical trials to control for the placebo effect.

Question 26

What is the placebo effect?

Answer 26

When patients improve solely because they believe they are receiving treatment, regardless of whether they are actually receiving the treatment ## Footnote The placebo effect highlights the importance of psychological factors in treatment outcomes.

Question 27

What is blinding in experiments?

Answer 27

Technique used to prevent participants and/or researchers from knowing who is receiving the experimental treatment and who is receiving the placebo ## Footnote Blinding reduces bias in the assessment of outcomes.

Question 28

Define single-blind study.

Answer 28

When only the participants are unaware of their treatment group assignment ## Footnote This method minimizes bias from participants but not from researchers.

Question 29

What is a double-blind study?

Answer 29

When both the participants and the researchers interacting with them are unaware of the treatment group assignments ## Footnote Double-blind studies are considered the gold standard in experimental research.

Question 30

What is a randomized, controlled, double-blind experiment?

Answer 30

Most reliable way to determine whether the explanatory variable is actually causing changes in the response variable ## Footnote This design helps to eliminate bias and confounding variables.

Question 31

Define **sample framing**.

Answer 31

The way a survey question is structured, influencing respondents' answers.

Question 32

True or false: **Volunteer response bias** occurs when participants self-select.

Answer 32

TRUE ## Footnote This bias often leads to unrepresentative samples, as those who volunteer may have specific interests.

Question 33

What is **convenience sampling**?

Answer 33

A non-probability sampling method where samples are taken from a group that is easy to reach.

Question 34

Fill in the blank: **Nonresponse bias** occurs when _______ do not participate in a survey.

Answer 34

selected individuals

Question 35

Define **response bias**.

Answer 35

A tendency of respondents to answer questions inaccurately or falsely.

Question 36

True or false: **Random sampling** eliminates all biases.

Answer 36

FALSE ## Footnote While it reduces bias, random sampling can still be affected by other factors.

Question 37

What is **selection bias**?

Answer 37

A distortion in statistical analysis resulting from the method of collecting samples.

Question 38

Fill in the blank: **Leading questions** can create _______ bias in surveys.

Answer 38

response

Question 39

Define **attrition bias**.

Answer 39

Bias that occurs when participants drop out of a longitudinal study, affecting the results.

Question 40

True or false: **Sampling error** is the same as bias.

Answer 40

FALSE ## Footnote Sampling error refers to the natural variability in samples, while bias indicates systematic error.

Question 41

Define **confounding variable**.

Answer 41

A variable that influences both the independent and dependent variables, potentially misleading results.

Question 42

True or false: **Correlation** implies causation.

Answer 42

FALSE ## Footnote Correlation indicates a relationship, but does not confirm one variable causes the other.

Question 43

Fill in the blank: A **confounding variable** can lead to _______ conclusions.

Answer 43

incorrect

Question 44

What is the difference between **correlation** and **causation**?

Answer 44

Correlation shows a relationship; causation indicates one event causes another.

Question 45

Identify a common **confounding variable** in health studies.

Answer 45

Age is often a confounding variable affecting health outcomes.

Question 46

What is an appropriate graph to represent a **C→C** (Categorical to Categorical) role-type classification?

Answer 46

two-way table ## Footnote A two-way table effectively displays the relationship between two categorical variables.

Question 47

What is an appropriate graph to represent a **C→Q** (Categorical to Quantitative) role-type classification?

Answer 47

side-by-side boxplot ## Footnote Side-by-side boxplots allow for comparison of quantitative data across different categories.

Question 48

What is an appropriate graph to represent a **Q→Q** (Quantitative to Quantitative) role-type classification?

Answer 48

scatterplot ## Footnote Scatterplots are used to visualize the relationship between two quantitative variables.