9. PENGUKURAN INSTRUMEN

8/8/2019 9. PENGUKURAN INSTRUMEN

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Exploring

Accounting Research

Measurement



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Concept

A generalized idea about a class of

objects, attributes, occurrences, or processes



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O perational Definition

Specifies what the researcher must do

to measure the concept under investigation



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K onsep -

Construct

K onsep merupakan ekspresi suatu abstraksiyang terbentuk melalui generalisasi dari

pengamatan terhadap fenomena-fenomena. Contoh:

Prestasi akademik merupakan abstraksi dari

kemampuan belajar mahasiswa. Bobot adalah konsep dari suatu benda yang

mempunyai karakteristik berat/ringan.



5

Tingkatan Abstraksi

K onsep

Tingkat abstraksi konsep tergantung dari mudahatau tidaknya fenomena yang diabstraksikan dapatdiidentifikasikan.

Contoh: Tanah adalah konsep aktiva tetap yang berujud

dan secara fisik mudah dikenali

Aktiva Tetap adalah lebih general

Sehingga aktiva merupakan konsep yang lebihakbstrak daripada tanah.

K onsep-konsep yang sangat abstrak/lebih abstrak sering disebut construct.



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Bagaimana construct dalam riset? Construct dalam riset tidak hanya diartikan

lebih abstrak, namun juga menyangkut apa

yang dipersepsikan orang.

Contruct dalam riset mempunyai makna

yang berbeda dengan konsep sebab

construct merupakan abstraksi darifenomena yang dapat diamati dari berbagai

dimensi.



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Contoh Construct K epuasan

K erja K epuasan kerja merupakan abstraksi dari

fenomena psikologis seorang terhadap

pekerjaan yang diamati berdasarkan

persepsi yang bersangkutan terhadap

berbagai dimensi lingkungan pekerjaan

yaitu: Dimensi Tugas yang dikerjakan, rekan-

rekan sekerja, atasannya, kompensasi,

promosi karir dll.



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Dimensi-dimensi construct yang tersusun

menjadi construct yang lebih abstraks yaitu

construct kepuasan kerja.

Misal dimensi contruct kepuasan terhadap

tugas dapat diobservasi berdasarkan

tanggapan seseorang mengenai sifat, jenis,kondisi atau hal lain yang ditugaskan

misalnya rutinitas tugas, kompelksitas tugas

dan sebagainya.



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Dengan demikian construct terdiri dari

konsep-konsep yang dapat diamati yang

selanjutnya untuk keperluan penelitian

diukur dengan menggunakan skala

pengukuran.

Construct yang diukur dengan skala tertentuselanjutnya menjadi variabel.



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PenggunaanC

onstruct Dengan mengoperasionalkan construct ke

dalam konsep-konsep yang dapat diamati

dan diukur menjadi variabel penelitian.

Menghubungkan construct yang lain

menjadi konstruksi teori. Misal: Inovatif

dan K reatif merupakan bagian dari fungsikepuasan kerja dan prestasi kerja.



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Variabel danC

onstruct Variabel merupakan segala sesuatu yang dapatdiberi berbagai macam nilai

Variabel merupakan penghubung antara contruct

yang abstract dengan fenomena yang nyata. Variabel merupakan proxy atau representasi dari

construct yang dapat diukur dengan berbagaimacam nilai.

Nilai variabel tergantung pada construct yangdiwakilinya.

Nilai variabel dapat berupa angka atau atributyang menggunakan ukuran atau skala dalam suatu

kisaran nilai.



THE MEASUREMENT

PR OCESS Two definitions

± Stevens²´assignment of numerals to objects or

events according to rules.´

± ³«the assignment of values to outcomes.´

Chapter foci

± Levels of measurement

± Reliability and validity



LEVELS OF MEASUREMENT

Variables are measured at one of these four levels

Qualities of one level are characteristic of the next level up The more precise (higher) the level of measurement, the

more accurate is the measurement process

Level of

MeasurementFor example Quality of Level

Ratio Rachael is 5 10 and Gregory is 5 5 Absolute zero

Interval Rachael is 5 taller than Gregory An inch is an inch is an inch

Ordinal Rachael is taller than Gregory Greater than

Nominal Rachael is tall and Gregory is short Different from



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Scale Series of items arranged according to value

for the purpose of quantification

A continuous spectrum



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Nominal Scale



NO

MINAL SC

ALE

Qualities Example What YouCan Say

What You CantSay

Assignment of labels

Gender(male orfemale)

Preference(like or dislike)

Voting record(for or

against)

Eachobservationbelongs in itsown category

An observationrepresents more or less than anotherobservation



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Ordinal Scale



ORDINAL S

CALE


What You CantSay

Assignment of values alongsome underlyingdimension

Rank in collegeOrder of finishinga race

Oneobservation isranked aboveor belowanother.

The amount that one variable ismore or less thananother



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Interval Scale



INT

ERVAL SC

ALE


What You CantSay

Equal distancesbetween points

Number of wordsspelled correctlyIntelligence test scoresTemperature

One scorediffers fromanother onsomemeasure that has equallyappearing

intervals

The amount of difference is anexact representation of differences onthe variablebeing studied



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Ratio Scale



RAT

IO

SC

ALE


What You CantSay

Meaningful andnon-arbitraryzero

AgeWeight Time

One value istwice asmuch asanother or noquantity of that variablecan exist

Not much!



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Scale Properties Uniquely classifies

Preserves order

Equal intervals

Natural zero



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Nominal Scale Properties Uniquely classifies

± Sammy Sosa # 21

± Barry Bonds # 25



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Ordinal Scale Properties

Uniquely classifies

Preserves order

Win, place, & show



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Interval Scale Properties Uniquely classifies

Preserves order

Equal intervals

± Consumer Price Index (Base 100)

± Fahrenheit temperature



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Ratio Scale Properties Uniquely classifies

Preserves order

Equal intervals

± Natural zero

± Weight and distance



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The Goal

of Measurement Validity



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Validity

The ability of a scale to measure what

was intended to be measured



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Reliability

The degree to which measures are

free from random error and thereforeyield consistent results



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Old Rifle New Rifle New Rifle

Sun glareLow Reliability High Reliability Reliable but Not

Valid

(Target A) (Target B) (Target C)

Reliability and Validity onT

arget



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Validity

FACE OR CONTENT

CONCURRENT PREDICTIVE

CRITERION VALIDITY CONSTRUCT VALIDITY

Vali i



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Reliability

TEST RETEST

STABILITY

EQUIVALENT FORMS SPLITTING HALVES

INTERNAL CONSISTENCY

RELIABILITY



WH

AT

IS ALLTH

EF

USS? Measurement should be as precise as possible

In psychology, most variables are probably

measured at the nominal or ordinal level But² how a variable is measured can determine

the level of precision



RELIABILITY AND

VALIDITY Reliability²tool is consistent

Validity²tool measures ³what-it-should´

Good assessment tools p

± Rejection of Null hypotheses

OR

± Acceptance of Research hypotheses



A CO NCEPTUAL DEFINITIO NOF RELIABILITY

Method ErrorObserved Score = True Score + Error Score

Trait Error




O bserved score

± Score actually observed

± C

onsists of two components True Score

Error Score


Trait Error




True score

± Perfect reflection of true value for individual

± Theoretical score


Trait Error




Error score

± Difference between observed and true score


Trait Error




Method error is due to characteristics of the test or testingsituation

Trait error is due to individual characteristics Reliability of the observed score becomes higher if error is

reduced!!


Trait Error



INC

REASING RELIABILITY

p Decreasing Error

Increase sample size

Eliminate unclear questions

Standardize testing conditions

Use both easy and difficult questions

Minimize the effects of external events Standardize instructions

Maintain consistent scoring procedures



HOW RELIABILITY IS

MEASURED Reliability is measured using a

± Correlation coefficient

± r test1test2

Reliability coefficients

± Indicate how scores on one test change relative

to scores on a second test ± Can range from -1.0 to +1.0 (perfect reliability)



TY

PESOF

RELIABILITY

Type of

Reliability

What It Is How You Do It What the Reliability

Coefficient Looks Like

Test-Retest A measure of stability Administer the same test/measure

at two different times to the same

group of participants

r test1test1

Parallel Forms A measure of

equivalence

Administer two different forms of

the same test to the same group of

participants

r form1form2

Inter-Rater A measure of

agreement

Have two raters rate behaviors and

then determine the amount of

agreement between them

Percentage of

agreements

Internal

Consistency

A measure of how

consistently each

item measures the

same underlying

construct

Correlate performance on each

item with overall performance

across participants

Cronbach¶s alpha



VALIDITY

A valid test does what it was designed to do

A valid test measures what it was designed

to measure



A CO NCEPTUAL DEFINITIO NOF VALIDITY

Validity refers to the test¶s results, not to the

test itself

Validity ranges from low to high, it is not

³either/or´

Validity must be interpreted within thetesting context



TY

PESOF

VALIDITY

Type of Validity What Is It? How Do You Establish It?

Content A measure of how well

the items represent the

entire universe of items

Ask an expert if the items assess what

you want them to

CriterionConcurrent A measure of how well a

test estimates a criterion

Select a criterion and correlate scores

on the test with scores on the criterion

in the present

Predictive A measure of how well a

test predicts a criterion

Select a criterion and correlate scores

on the test with scores on the criterion

in the future

Construct A measure of how well a

test assesses some

underlying construct

Assess the underlying construct on

which the test is based and correlate

these scores with the test scores



HOW TO ESTABLISH

CO NSTRUCT VALIDITY OF A NEW TEST

Correlate new test with an established test

Show that people with and without certain traits

score differently

Determine whether tasks required on test are

consistent with theory guiding test development



MULTITRAIT-

MULITMETHOD MATRIX

Convergent validity²different methods yield similar results

Discriminant validity²different methods yield different results

Method 1

Paper and Pencil

Method 2

Activity Level

Monitor

Method 1

Paper and Pencil

Method 2

Activity Level

Monitor

Trait 1

Method 1

Paper and Pencil Moderate Low

Impulsivity Method 2

Activity Level

Monitor

Moderate

Trait 2

Method 1

Paper and Pencil

Activity

Level

Method 2

Activity LevelMonitor

Low

Trait 1

Impulsivity

Trait 2

Activity Level



THE RELATIO NSHIP

BETWEEN RELIABILITY AND VALIDITY

A valid test must be reliable

But

A reliable test need not be valid

9. PENGUKURAN INSTRUMEN

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