64
Research Methods for Business 1 Chapter 9 Data Collection Methods: Questionnaires © 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

  • Upload
    others

  • View
    0

  • Download
    0

Embed Size (px)

Citation preview

Page 1: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

1

Chapter 9

Data Collection Methods: Questionnaires

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 2: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Questionnaire Design

• DefinitionA questionnaire is a pre-formulated, written set of questions to which the respondent records his answers

• Steps

1. Determine the content of the questionnaire

2. Determine the form of response

3. Determine the wording of the questions

4. Determine the question sequence

5. Write cover letter

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 3: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

1. Questionnaire content

• FrameworkNeed information for all constructs in framework

• Measurement: Operationalizing– Objective construct:

• 1 element/items=> 1 question

– Subjective construct: • multiple elements/items

=> multiple questions

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 4: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

2. Response format

• Closed vs. Open-ended questions– Closed questions

• Helps respondents to make quick decisions

• Helps researchers to code

– Open-ended question• First: unbiased point of view

• Final: additional insights

• Complementary to closed question: for interpretation purpose

• Cfr. Measurement: Response scales

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 5: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

• Avoid double-barreled questions

• Avoid ambiguous questions and words

• Use of ordinary words

• Avoid leading or biasing questions

• Social desirability

• Avoid recall depended questions

3. Question wording

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 6: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

• Use positive and negative statements

– Dresdner delivers high quality banking service

Dresdner has poor customer operational support

– Avoid double negatives

• Limit the length of the questionsRules of thumb:

– < 20 words

– < one full line in print

Question wording

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 7: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

4. Question sequence

Personal and sensitive data at the end© 2012 John Wiley & Sons Ltd.

www.wiley.com/college/sekaran

Page 8: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

• The cover letter is the introductory page of the questionnaire

• It includes:

– Identification of the researcher

– Motivation for respondents to fill it in

– Confidentiality

– Thanking of the respondent

5. Cover letter

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 9: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

9

Chapter 7

Data Collection Methods: Introduction and Interviews

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 10: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Sources of Data

• Primary data: information obtained firsthand by the researcher on the variables of interest for the specific purpose of the study.

• Examples: individuals, focus groups, panels

• Secondary data: information gathered from sources already existing.

• Examples: company records or archives, government publications, industry analyses offered by the media, web sites, the Internet, and so on.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 11: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Interviews

• Unstructured interviews:

– the interviewer does not enter the interview setting with a planned sequence of questions to be asked of the respondent.

• Structured interviews:

– Conducted when it is known at the outset what information is needed.

– The interviewer has a list of predetermined questions to be asked of the respondents either personally, through the telephone, or via the computer.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 12: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Personal interview

• Advantages– Can clarify doubts about questionnaire

– Can pick up non-verbal cues

– Relatively high response/cooperation

– Special visual aids and scoring devises can be used

• Disadvantages– High costs and time intensive

– Geographical limitations

– Response bias / Confidentiality difficult to be assured

– Some respondents are unwilling to talk to strangers

– Trained interviewers

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 13: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Telephone interview

• Advantages– Discomfort of face to face is avoided

– Faster / Number of calls per day could be high

– Lower cost

• Disadvantages– Interview length must be limited

– Low response rate

– No facial expressions

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 14: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Self-administered

• Advantages– Lowest cost option

– Expanded geographical coverage

– Requires minimal staff

– Perceived as more anonymous

• Disadvantages– Low response rate in some modes

– No interviewer intervention possible for clarification

– Cannot be too long or complex

– Incomplete surveys

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 15: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Projective Methods• Word association techniques:

– Asking the respondent to quickly associate a word with the first thing that comes to mind.

– Often used to get at true attitudes and feelings.

• Thematic apperception tests (TAT):– Call for respondent to weave a story around a picture

that is shown. – To trace patterns and personality characteristics of

respondents.

• Inkblot tests: – Form of motivational research, uses colored inkblots

that are interpreted by respondents.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 16: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

16

Chapter 8

Data Collection Methods: Observation

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 17: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Observation

• Observation involves going into ‘the field’, -the factory, the supermarket, the waiting room, the office, or the trading room -watching what workers, consumers, or day traders do, and describing, analyzing, and interpreting what one has seen.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 18: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Examples

• Shadowing a Wall Street broker engaged in his daily routine.

• Observing in-store shopping behavior of consumers via a camera.

• Sitting in the corner of an office to observe how a merchant bank trader operates.

• Working in a plant to study factory life.

• Studying the approach skills of sales people disguised as a shopper.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 19: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Key dimensions characterizing type of observation

• Controlled versus Uncontrolled Observational Studies

• Participant versus Non-Participant Observation

• Structured versus Unstructured Observational Studies

• Concealed versus Unconcealed observation

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 20: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Participant Observation

• The participatory aspect:

– Complete participation

– Moderate participation

– Active participation

• To what extent should I participate?

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 21: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Participant Observation

• The observation aspect

– Obtaining permission

– Finding a ‘sponsor’

– Establishing rapport

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 22: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

What to observe?

• Descriptive observation stage:

– Space

– Objects

– Actors

– Feelings

– Events

Spradly, 1980

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 23: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

What to observe?

• Focused and selective observation stage:– Look for a story line

– Sort out regular from irregular activities

– Look for variation in the storyline

– Look for negative cases or exceptions

– Develop a plan for systematic observation if needed

DeWalt and DeWalt, 2002

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 24: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Structured observation

• Looks selectively at predetermined phenomena

• Different levels of structure

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 25: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Coding schemes

• Focus

• Objective

• Ease of use

• Mutually exclusive and collectively exhaustive

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 26: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Standard Coding Schemes

• Simple checklist

• Sequence record

• Sequence record on time scale

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 27: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

27

Chapter 12

Measurement of Variables: Scaling, Reliability, Validity

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 28: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Scale

• Scale: tool or mechanism by which individuals are distinguished as to how they differ from one another on the variables of interest to our study.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 29: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Nominal Scale

• A nominal scale is one that allows the researcher to assign subjects to certain categories or groups.

• What is your department?

O Marketing O Maintenance O Finance

O Production O Servicing O Personnel

O Sales O Public Relations O Accounting

• What is your gender?

O Male

O Female

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 30: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Nominal Scale

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 31: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Ordinal Scale

• Ordinal scale: not only categorizes variables in such a way as to denote differences among various categories, it also rank-orders categories in some meaningful way.

• What is the highest level of education you have completed?O Less than High School O High School/GED Equivalent O College Degree O Masters Degree O Doctoral Degree

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 32: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Ordinal Scale

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 33: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Interval Scale

• Interval scale: whereas the nominal scale allows us only to qualitatively distinguish groups by categorizing them into mutually exclusive and collectively exhaustive sets, and the ordinal scale to rank-order the preferences, the interval scale lets us measure the distance between any two points on the scale.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 34: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Interval scale

• Circle the number that represents your feelings at this particular moment best. There are no right or wrong answers. Please answer every question.

1. I invest more in my work than I get out of it

I disagree completely 1 2 3 4 5 I agree completely

2. I exert myself too much considering what I get back in return

I disagree completely 1 2 3 4 5 I agree completely

3. For the efforts I put into the organization, I get much in return

I disagree completely 1 2 3 4 5 I agree completely

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 35: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Interval scale

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 36: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Ratio Scale

• Ratio scale: overcomes the disadvantage of the arbitrary origin point of the interval scale, in that it has an absolute (in contrast to an arbitrary) zero point, which is a meaningful measurement point.

• What is your age?

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 37: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Ratio Scale

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 38: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Properties of the Four Scales

• Insert Table 12.1 here

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 39: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Goodness of Measures

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 40: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Validity

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 41: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Reliability

• Reliability of measure indicates extent to which it is without bias and hence ensures consistent measurement across time (stability) and across the various items in the instrument (internal consistency).

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 42: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Stability

• Stability: ability of a measure to remain the same over time, despite uncontrollable testing conditions or the state of the respondents themselves.– Test–Retest Reliability: The reliability coefficient

obtained with a repetition of the same measure on a second occasion.

– Parallel-Form Reliability: Responses on two comparable sets of measures tapping the same construct are highly correlated.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 43: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Internal Consistency

• Internal Consistency of Measures is indicative of the homogeneity of the items in the measure that tap the construct.

– Interitem Consistency Reliability: This is a test of the consistency of respondents’ answers to all the items in a measure. The most popular test of interitem consistency reliability is the Cronbach’s coefficient alpha.

– Split-Half Reliability: Split-half reliability reflects the correlations between two halves of an instrument.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 44: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

44

Chapter 13

Sampling

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 45: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Sampling

• Sampling: the process of selecting a sufficient number of elements from the population, so that results from analyzing the sample are generalizable to the population.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 46: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Relevant Terms - 1

• Population refers to the entire group of people, events, or things of interest that the researcher wishes to investigate.

• An element is a single member of the population.

• A sample is a subset of the population. It comprises some members selected from it.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 47: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Relevant Terms - 2

• Sampling unit: the element or set of elements that is available for selection in some stage of the sampling process.

• A subject is a single member of the sample, just as an element is a single member of the population.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 48: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Relevant Terms - 3

• The characteristics of the population such as µ (the population mean), σ (the population standard deviation), and σ2 (the population variance) are referred to as its parameters. The central tendencies, the dispersions, and other statistics in the sample of interest to the research are treated as approximations of the central tendencies, dispersions, and other parameters of the population.

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 49: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Statistics versus Parameters

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 50: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Advantages of Sampling

• Less costs

• Less errors due to less fatigue

• Less time

• Destruction of elements avoided

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 51: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

The Sampling Process

• Major steps in sampling:

– Define the population.

– Determine the sample frame

– Determine the sampling design

– Determine the appropriate sample size

– Execute the sampling process

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 52: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Sampling Techniques

• Probability versus nonprobability sampling

• Probability sampling: elements in the population have a known and non-zero chance of being chosen

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 53: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Sampling Techniques• Probability Sampling

– Simple Random Sampling

– Systematic Sampling

– Stratified Random Sampling

– Cluster Sampling

• Nonprobability Sampling– Convenience Sampling

– Judgment Sampling

– Quota Sampling

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 54: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Simple Random Sampling

• Procedure– Each element has a known and equal chance of being selected

• Characteristics– Highly generalizable

– Easily understood

– Reliable population frame necessary

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 55: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Systematic sampling

• Procedure– Each nth element, starting with random choice of an element

between 1 and n

• Characteristics– Idem simple random sampling

– Easier than simple random sampling

– Systematic biases when elements are not randomly listed

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 56: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Cluster sampling• Procedure

– Divide of population in clusters

– Random selection of clusters

– Include all elements from selected clusters

• Characteristics– Intercluster homogeneity

– Intracluster heterogeneity

– Easy and cost efficient

– Low correspondence with reality

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 57: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Stratified sampling

• Procedure– Divide of population in strata

– Include all strata

– Random selection of elements from strata• Proportionate

• Disproportionate

• Characteristics– Interstrata heterogeneity

– Intrastratum homogeneity

– Includes all relevant subpopulations

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 58: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

(Dis)proportionate stratified sampling

• Number of subjects in total sample is allocated among the strata (dis)proportional to the relative number of elements in each stratum in the population

• Disproportionate case:– strata exhibiting more variability are sampled more than proportional

to their relative size

– requires more knowledge of the population, not just relative sizes of strata

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 59: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Example

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 60: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Overview

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 61: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Choice Points in Sampling Design

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 62: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Tradeoff between precision and confidence

We can increase both confidence and precision by increasing the sample size

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 63: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Sample size: guidelines

• In general: 30 < n < 500

• Categories: 30 per subcategory

• Multivariate: 10 x number of var’s

• Experiments: 15 to 20 per condition

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran

Page 64: Questionnaires - Personal Website of Ahmad Othman · 2014-11-04 · –Can pick up non-verbal cues –Relatively high response/cooperation –Special visual aids and scoring devises

Research Methods for Business

Sample Size for a Given Population Size

© 2012 John Wiley & Sons Ltd. www.wiley.com/college/sekaran