KESAHAN

KESAHAN - VALIDITY

bermaksud sejauh mana alat mengukur apa yang sepatutnya di ukur

menurut:

: Youngman & Eggleston, 1982; Sax & Newton, 1997 - Kesahan bermaksud kebolehan
   ujian mengukur apa yangsepatutnya diukur

: Ary et. al, 2005 - kesahan ialah sejauhmanakahdapatan kajian atau data yang dikumpul
  dapat memberikan penjelasan yangbermakna kepada kajian yang dilakukan
 

: Mohd Majid Konting, 1990 - Kesahan sesuatu alat pengukuran merujuk kepada sejauh
  manakah alat yangdigunakan mengukur data yang dikehendakiuntuk mencapai objektif
  kajian .

: Fraenkel & Wallen (1996) - kesahan boleh dibuktikan melalui beberapa kaedah seperti
 kesahan isi kandungan (content validity), kesahan telahan (predictive validity), kesahan
 serentak (concurrent validity) dan kesahan gagasan (construct validity)

 

3 ASPEK KESAHAN.

1. Kesahan Gagasan

 - based on internal structure

 - construct (determination of the significance, meaning, purpose, and use of the
   scores)

 - To measure several components or dimensions of a construct.

 - Use Factor Analysis to analyzes correlations among test items and tells you the

   number of factors present. Its tell you whether the test is unidimensional or

   multidimensional.

 - Unidimensional – all the item measure are single construct.

 - Multidimensional – different set of item tap different construct or different

   component of a broader construct.

- Internal Structure...

•          Factor analysis tell you how many dimensions or factors your test items   

      represent.

•          Also can obtain a measure of test homogeneity (i.e., the degree to which the

      different items measure the same construct or trait)

•          Use coefficient alpha (Alpha Cronbach) for the test of homogeneity.

•         If the alpha is low (e.g., <.70) for the test, then some items might be measuring 

      different constructs or some items might be bad.

•          Examine the items that are contributing to your low coefficient alpha and

      consider eliminating or revising them.

2. Kesahan Kriteria

 

- based on relations to other variables

 

- criterion - referenced (scores are a predictor of an outcome or criterion they are

 

  expected to predict) - concurrent evidence and predective evidence

 

- criterion validity

 

•Obtained by relating your test scores to a relevant criterion.

•A criterion is the standard or benchmark that you want to predict accurately on the basis of

 scores from your test.

•Sejauh mana kaitan antara alat dengan kriteria luaran yang berkecuali (sama ada item

 mengukur kriteria yang hendak diukur).

•Ditentukan dengan analisis korelasi antara dua set markah.

•Calculate correlation coefficients for the study of validity – validity coefficients.

Concurrent Validity

refers to a measurement device’s ability to vary directly with a measure of the same construct or indirectly with a measure of an opposite construct.  It allows you to show that your test is valid by comparing it with an already valid test.  Administering the focal test and criterion test at approximately the same point in time (i.e., concurrently) and then correlating the two set of scores.  If the two sets of scores highly correlated, you have concurrent evidence.

Predictive Validity
 

-Obtain predictive evidence of validity by measuring your participants at one point in time on

 your test and then, at a future time, measuring them on the criterion measure.

- Take more time and effort than concurrent evidence, but it can provide superior evidence

   that your test does what you want it to do.

 

3. Kesahan Kandungan

 

- based on content

 

- content (representative of all possible questions that could be asked)

 

- content validation is usually carried out by experts

 

- Sejauh mana alat merangkumi kandungan sesuatu bidang.

- Matlamat utama ialah untuk memastikan semua isi dan kandungan bidang yang diukur

  menggambarkan bidang tersebut.

 - Berdasarkan kepada skop dan objektif dan kandungan sesuatu bidang yang dikaji.

 - Pendapat pakar atau penilai luar diperlukan bagi menilai kesesuaian butiran bagi domain

   yang dipilih.

 

Content Validity.

 

- is concerned with a test’s ability to include or represent all of the content of a

  particular construct.  The question “1 + 1 = ___” may be a valid basic addition

  question.  Would it represent all of the content that makes up the study of

  mathematics?  It may be included on a scale of intelligence, but does it represent all

  of intelligence?  The answer to these questions is obviously no.  To develop a valid

  test of intelligence, not only must there be questions on math, but also questions on

  verbal reasoning, analytical ability, and every other aspect of the construct we call

  intelligence.  There is no easy way to determine content validity aside from expert

  opinion.

 

1.Do the items appear to represent the thing you are trying to measure?

2.Does the set of items underrepresented the construct’s content (i.e., have you

   excluded any important content areas or topics?)

3.Do any of the items represent something other than what you are trying to

   measure (i.e., have you included any irrelevant items?)

 

Sebelum sesuatu instrumen itu dikatakan mempunyai kesahan kandungan, lima

syarat ini perlu dipenuhi:

1.Bidang kandungan mestilah dinyatakan dalam bentuk tingkah laku yang

   secara umum diterima maknanya.

 

2.Bidang mestilah dihuraikan dengan jelas.

3.Bidang mestilah relevan dengan tujuan penggunaan ujian.

4.Hakim-hakim yang berkelayakan mestilah bersetuju bahawa bidang telah

   disampel secara mencukupi.