Quantitative techniques for psychology

QUANTITATIVE TECHNIQUES FOR PSYCHOLOGY

DR.S.THENMOZHI

Lesson -1Introduction to Quantitative methods&

Measurement

• TYPES OF RESEARCH

Types of Research

Nomothetic

QuantitativeQualitative

Idiographic

Classification of Psychological Research

• Descriptive Research• Correlation Research• Experimental Research• Naturalistic observation• Self Report

Quantitative Techniques

• Need• Ad vantages• Limitations• Classification• Tests

MEASUREMENT

Nominal Scale

Ordinal Scale

Interval Scale

Ratio scale

scales

• Nominal – Mere No s 1 2 3 4 5 6 7 8 9• Ordinal – Ist Rank, II Rank ………• Interval - Equal Intervel - temperature• Ratio – Absolute Zero , IQ levelss

ERRORS IN MEASUREMENT

Respondents FactorsSituationMeasurer EffectInstrument Tools

LESSON – 2

• CONCEPT OF OBJECTIVITY and Types of Tests

LESSON -3 TEST CONSTRUCTION

• QUESTIONNAIRES• Questionaire as per Goode (1981) refers to a

device for securing answers to questions by using a form which the Respondents fills in himself.

Advantages & Disadvantages

• Advantages – Low cost. Free from the bias of the interviewer, Adequate time, Large samples

• Disadvantages – Low rate of return, only educated, no control once it is sent, slowest method, possibility of ambiguous, untrue, incomplete answers

Types of Qs

• Standardized / structured Questionnaire• Nonstandard zed / unstructured

Questionnaire• Closed end/ open ended Questionnaire

Types of Responses

• True /False items• Multiple Choice items• open ended items

Likert's Attitude ScaleThis is multiple agree – disagree 5

point scale

ADMINSTRATION OF Qs

• Face to Face• Written administration• Computerized administration• Telephone administration

Psychological Test

• Test in Psychology are a formal technique of measuring feelings, abilities, traits, beliefs and behavior in a particular situation.

TYPES OF TESTS • Performance / Verbal Tests• Paper Pencil Test• Personality Tests• Situational Tests• Projective Tests

• Individual test /group test • Speed test and power test• Researcher made/ standardized test• Oral/ written/ performance test

Lesson -4 TEST STANDARDIZATION

• The characteristics of Good test it should be standardized test

• Reliability• Validity• Objectivity• Norms

Test construction

• 1. Planning the Test• 2.Preparing the preliminary draft of the test• 3.Trying out preliminary draft of the test• 4.Evaluating the test• 5.Construction of the final Draft of the test

Item writing

• 1.Address single issue per item• Avoid bais• Make alternatives clear• Beware of social desirability• Determine the format of item• Sequence the item

Item analysis

Item analysis is a process which examines student responses to individual test items (questions) in order

to assess the quality of those items and of the test as a whole. Item analysis is especially valuable in improving items which will be used again in later tests, but it can also be used to eliminate ambiguous or misleading items in a single test administration. In addition, item analysis is valuable for increasing instructors' skills in test construction, and identifying specific areas of course content which need greater emphasis or clarity.

2 Characteristics of Item analysis - Difficulty value and Discriminative power

Reliability & Validity

• Reliability refers to the consistency of scores obtained by the same persons when they are reexamined with the same test on different occasions. (consistency )

• Validity refers to the concern what the test measures and how well it does so.The degree to which the test measures what it purports to measure.

Types of Reliability

• i . Test Retest Reliability• ii. Alternate form Reliability• iii. Split Half Reliability• Iv. Inter rater Reliability ( scorer Reliability)

The standard Error of measurement Analysis of variance

Types of Validity

• Types of Valitidity• Content Validity• Face validity• Criterion related validity – Predictive &

concurrent validity• Construct validity• Factorial validityThe error of Estimate - Correlation coeficient

Norms

• Freeman defines a norm as norm in measurement as the ‘average or standard score on a particular test made by a specified population.

• It is a device of transforming raw scores into standard scores in a group.

VARIABLES

• What is a Variable?

• Types of variables• IV & DV• Confounding variable• Quantitative & Categorical variable• Continuous & Discrete Variable

Sampling Design

• What is a sample ?• Universe – Population – Samples

• Systematic Sampling• Simple Random Sampling• Stratified Random Sampling• Purposive Sampling• Cluster Sampling• Convienence Sampling

LESSON- 5 RESEARCH DESIGNS

• RESEARCH – knowing – ‘what’ of a study

• Research Problem – The variables to be studied

• Formulate the Hypothesis to be tested• To test the Hypothesis research Design is

required.

RD

• Green etal (2008)defines Research Design as ‘the specification of methods and procedures for acquiring the information needed’.

• Purpose of RD• 1.Maximise the variance• 2.control extraneous variance• 3.minimize error varience

Important Elements of RD

• Introduction – Reserch Plan/Problem• Statement of Problem• Review of Literature• Scope of the study\Objectives of the

studyConceptual model• Hypotheses• Operational Def of Variables• Significance of the study• Sampling design/plan

• Tools• Analysis• Time budjet• Financial budjet

Classification of RD Research DesignExploraory RD conclusive RD

Descriptive Research Casual Research

cross sectional Design Longitudinal Design

Single cross sectional Design & Multiple cross sectional Design

Informal Research Design

• Exploratory Research Design• Secondary resource analyses• Comprehensive case method• Expert opinion survey• Focus group Discussions.