Lecture 1

Question 1

Statistics

Answer 1

the science of data that involves designing, collecting, classifying, summarizing, organizing, analyzing, and interpreting numerical and categorial information

Question 2

what questions can statistics answer?

Answer 2

what kind and how much data needs to be collected? how should we organize and summarize the data? how can we analyze the data and draw conclusions from it? how can we assess the strength of the conclusions and evaluate their uncertainty?

Question 3

Descriptive statistics

Answer 3

utilizes numerical or graphical methods to explore data; includes the construction of graphs, charts, and tables, and the calculation of various descriptive measures such as averages, measures of variation, and percentiles

Question 4

inferential statistics

Answer 4

utilizes sample data to make estimates, decisions, predictions, or other generalization about a large set of data

Question 5

population

Answer 5

collection of all individuals or items under consideration in a statistical study

Question 6

sample

Answer 6

part of the population from which information is collected

Question 7

variable of interest

Answer 7

characteristic or property of an individual experimental unit. Often represented numerically by a measurement

Question 8

statistical inference

Answer 8

is an estimate or prediction or other generalization about a population based on information contained in a sample

Question 9

experimental unit

Answer 9

set of units that we are interested in studying

Question 10

quantitative

Answer 10

measurements that are recorded on a naturally occurring numerical scale

Question 11

qualitative or categorical

Answer 11

measurements that cannot be measured on a naturally numerical scale. they can only be classified into groups or categories

Question 12

designed experiment

Answer 12

data collection method where the researcher exerts full control over the characteristics of the experimental units sampled. these experiments typically involve a group of experimental units that are assigned the treatment and an untreated (control) group

Question 13

observational study

Answer 13

data collection method where the experimental units sampled are observed in their natural setting. No attempt is made to control the characteristics of the experimental units sampled

Question 14

representative sample

Answer 14

exhibits characteristics typical of those possessed by the target population

Question 15

simple random sample

Answer 15

subset of a statistical population in which each member of the subset has an equal probability of being chosen

Question 16

stratified random sample

Answer 16

typically used when the experimental units associated with the population can be separated into two groups (strata)

Question 17

cluster sample

Answer 17

used when it is more convenient and logical to sample natural groupings (clusters) of experimental units first, then collect data from all units within each cluster

Question 18

systematic sampling

Answer 18

involves selecting every kth unit from a list

Question 19

efficiency

Answer 19

time and money

Question 20

accuracy

Answer 20

an estimator is accurate if it is both unbiased and precise

Question 21

bias

Answer 21

a systematic difference between an estimator and the population parameter

Question 22

in what ways can bias be introduced into an estimator

Answer 22

measurement error, coverage error, nonresponse error, the estimator itself (MCNE)

Question 23

selection bias

Answer 23

results when a subset of experimental units in the population has little or no chance of being selected for the sample

Question 24

nonresponse bias

Answer 24

type of selection bias that results when data on all experimental units in a sample are not obtained

Question 25

measurement error

Answer 25

refers to inaccuracies in the values of the data collected. In surveys, the error may be due to ambiguous or leading questions and the interviewer’s effect on the respondent

Question 26

data analysis path

Answer 26

formulate the research problem, define population and sample, collect the data, do descriptive analysis, use appropriate statistical methods to solve the research problem, report the results,

Question 27

statistical thinking

Answer 27

involves applying rational thought and the science of statistics to critically assess data and inferences. Fundamental to the thought process is that variation exists in populations of data.

Question 28

unethical statistical practice

Answer 28

includes introducing intentional bias into the sample or inferences