Module 1.2 Basic Concepts in Inferential Statistics

Question 1

Typically, statistics has two broad objectives: to _______ and to ________

Answer 1

to describe and to infer

Question 2

refers to the tools used to describe a mass of data in a clear, concise, and informative way through the methods of organizing, summarizing, and presenting data

Answer 2

descriptive statistics

Question 3

refers to the tools used to analyze the information from the sample to make generalizations or predictions about the population

Answer 3

inferential statistics

Question 4

aims to generate information about the population given a sample from that population

Answer 4

inferential statistics

Question 5

Differentiate descriptive and inferential statistics

Answer 5

Descriptive Statistics - refers to the tools used to describe a mass of data in a clear, concise, and informative way through the methods of organizing, summarizing, and presenting data

Inferential Statistics - refers to the tools used to analyze the information from the sample to make generalizations or predictions about the population; aims to generate information about the population given a sample from that population

Question 6

Based on the data on recorded births from January to December 2021 in the Philippines, the most common baby names for males and females are Jacob and Althea, respectively.

What example of statistics is this?

Answer 6

descriptive statistics

Question 7

True or False
A graphical presentation of the Philippine population by age group and gender is an example of inferential statistics

Answer 7

False, it is an example of descriptive statistics

Question 8

The 2nd quarter 2023 Social Weather Survey (SWS) found that 45% of Filipino families consider themselves as poor. The June 2023 SWS was conducted from June 28 to July 1, 2023 using face-to-face interviews of a random sample of 1,500 adults nationwide.

This is an example of a/n _______ statistics

Answer 8

inferential statistics

Question 9

Descriptive or Inferential

Since its first participation in 1924, the Philippines has won 14 medals at the Olympic games

Answer 9

Descriptive statistics

Question 10

A student recenty read an article which says that 70% of UPLB students are satisfied with their choice of degree course. This was the result of a surve conducted to 7500 UPLB students registered last semester

Descriptive or Inferential?

Answer 10

Inferential Statistics

Question 11

True or False:
A research firm conducted a survey to determine the Filipinos’ level of trust in foreign countries. Of the 1,800 respondents, 51% of them have little trust in China.

This is an example of a descriptive statistics

Answer 11

True, the 51% result is only describing the sample of 1800, not an entire population

Question 12

The sample is gained from the ________ via the process ________; after characterizing the sample, the data obtained will be used to make __________ on the population, making use of the ________ method of drawing conclusions

bonus: Where is this process present?

Answer 12

population, sampling;
inferences and/or generalizations, inductive

Question 13

Modified True or False:
the sample must be representative of the population under study

Answer 13

True

Question 14

The only assurance if the sample is representative of the population comes from the ____________

Answer 14

method used to select the sample

Question 15

In _______ sampling, elements are selected for the sample using an objective chance mechanism

Answer 15

probability sampling

Question 16

________ sampling requires that each unit in the population has a known and non-zero chance of selection

bonus: explain what the statement meant as known and non-zero chance of selection

Answer 16

probability

bonus: non-zero chance means that everyone has a chance to be selected; known means that the probability to be chosen is known

Question 17

also known as random samples

Answer 17

probability samples

Question 18

probability samples allow the __________

Answer 18

drawing of valid generalizations about the population under study

Question 19

samples are obtained haphazardly, selected purposively, or taken as volunteers

Answer 19

nonprobability sampling

Question 20

Modified True or False:
In nonprobability sampling, the probabilities of selection are unknown

Answer 20

True

Question 21

___________ samples should not be used for statistical inference

Answer 21

nonprobability samples

Question 22

Types of Samples

Answer 22

Probability and Non-probability samples

Question 23

characteristics of probability samples

bonus: another name for probability samples

Answer 23

1. probabilities of selection are known and non-zero
2. obtained using randomization (some objective chance mechanism)
3. requires the use of sampling frame (complete listing of the elements of the universe)
4. allows drawing of valid generalizations about the population

Question 24

Basic probability sampling techniques

bonus: explain each

Answer 24

1. simple random sampling - assigns equal probabilities of selection to each possible sample
2. stratified random sampling - the universe is divided into stratas (mutually exclusive sub-universes) and an independent simple random samples are obtained from each stratum
3. systematic random sampling - adopts a skipping patern in the selection of sample units
4. cluser sampling - universe is divided into clusters (mutually exclusive sub-groups) and a random cluster will be selected and their elements will be considered the sample

Question 25

Differentiate strata and clusters

Answer 25

strata - mutually exclusive sub-universes - used in stratified random sampling cluster - mutually exclusive sub-groups - used in cluster sampling

Question 26

In a study that aims to elicit responses for sensitive questions such as reasons for engaging in premarital sex, participants in the study are usually chosen purposively. The respondents’ profiles were already identified and their backgrounds on the topic were known before the conduct of the survey. Type of sampling?

Answer 26

Nonprobability sampling

Question 27

If you want to study a rare disease, you will go to the doctor specializing in the rare disease. After this, the doctor will recommend the patient with that rare disease. Then you will ask the patient if he knew someone having the disease. As you go along the sampling process, the number of samples increases. Type of sampling? bonus: more specific

Answer 27

Nonprobability sampling bonus: snowball sampling

Question 28

When do you use simple random sampling?

Answer 28

1. If the elements are homogenous with respect to the characteristic under study 2. If the elements are not so spread out geographically

Question 29

When to use stratified random sampling?

Answer 29

1. If the population is heterogeneous in terms of the characteristic under study 2. If a separate analysis will be performed for certain groups

Question 30

When to use systematic sampling?

Answer 30

1. If the population is heterogeneous in terms of the characteristic under study 2. If a separate analysis will be performed for certain groups

Question 31

When to use cluster sampling?

Answer 31

1. If there is no available list of units in the population 2. If cost is of great consideration

Question 32

concerned with finding a value or range of values for an unknown parameter of interest

Answer 32

estimation

Question 33

deals with verifying a claim or a conjecture about a parameter or distribution of the population under consideration

Answer 33

test of hypothesis

Question 34

define estimation and test of hypothesis

Answer 34

Estimation - concerned with finding a value or range of values for an unknown parameter of interest Test of Hypothesis - deals with verifying a claim or a conjecture about a parameter or distribution of the population under consideration

Question 35

In statistical inference, statistic is used to estimate the __________ of interest

Answer 35

parameter Notes: *parameter - summary measure of population *inferential statistics - generates information about the population given a sample *estimation - concerned with finding a value or range of values for an unknown parameter of interest

Question 36

formula for computing the statistic using sample data

Answer 36

estimator

Question 37

realization of the estimator bonus: meaning of [realization]

Answer 37

estimate bonus: numerical value

Question 38

differentiate estimation, estimator, and estimate

Answer 38

estimation - concerned with finding a value or range of values for an unknown parameter of interest estimator - formula for computing the statistic using sample data estimate - realization (numerical value) of the estimator