Sampling

Sampling involves any procedure that draws conclusions based on measurements of a portion of the population. In other words, a sample is a subset from a larger population. If certain statistical procedures are followed, a researcher need not select every item in a population because the results of a good sample should have the same characteristics as the population as a whole. Of course, when errors are made, samples do not give reliable estimates of the population. (Zikmud; 2009; 68)

Sampling is defined in terms of the population being studied. A population (universe) is any complete group—for example, of people, sales territories, stores, or college students that shares some common set of characteristics. The term population element refers to an individual member of the population. (Zikmud; 2009; 387)

Referensi:

Zikmund William,  Babin Barry J, Carr John C, Griffin Mitch; 2009. Business Research Method, Eight Edition.

Validity & Reliability

Validity is the most critical criterion and indicates the degree to which an instrument measures what it is supposed to measure. Validity can also be thought of as utility. In other words, validity is the extent to which differences found with a measuring instrument reflect true differences among those being tested. But the question arises: how can one determine validity without direct confirming knowledge? The answer may be that we seek other relevant evidence that confirms the answers we have found with our measuring tool. What is relevant, evidence often depends upon the nature of the research problem and the judgement of the researcher. But one can certainly consider three types of validity in this connection: (i) Content validity; (ii) Criterion-related validity and (iii) Construct validity. (Khotari; 2004; 75) .

Reliability

The test of reliability is another important test of sound measurement. A measuring instrument is reliable if it provides consistent results. Reliable measuring instrument does contribute to validity, but a reliable instrument need not be a valid instrument. For instance, a scale that consistently overweighs objects by five kgs., is a reliable scale, but it does not give a valid measure of weight. But the other way is not true i.e., a valid instrument is always reliable. Accordingly reliability is not as valuable as validity, but it is easier to assess reliability in comparison to validity. If the quality of reliability is satisfied by an instrument, then while using it we can be confident that the transient and situational factors are not interfering (Khotari; 2004; 75).

Referensi

Khotari.C.R 2004; 75) Research Methodologi Methods and Tehnicques. New Age International (P) Ltd., Publishers: Ansari Road, Daryaganj, New Delhi - 110002

Penelitian Deskriptif

Penelitian deskriptif   adalah untuk menggambarkan karakteristik objek, orang, kelompok, organisasi, atau lingkungan. Dengan kata lain, penelitian deskriptif mencoba untuk menggambarkan dari situasi tertentu dengan menggunakan pertanyaan siapa, apa, kapan, di mana, dan bagaimana  (Zikmund, Babin, Carr, Griffin, 2009; 55)

Menurut ( Cohen, Manion dan Morrison, 2.007 205) penelitian deskriptif berkaitan dengan bagaimana apa atau apa yang ada terkait dengan beberapa peristiwa sebelumnya yang telah mempengaruhi atau terpengaruh peristiwa atau kondisi saat ini.

Penelitian deskriptif menggambarkan perilaku, pikiran, atau perasaan kelompok tertentu individu. Sebaai contoh yang paling umum dari penelitian deskriptif murni adalah jajak pendapat umum, yang menggambarkan sikap dari kelompok masyarakat tertentu (Mark R. Leary, 2001; 25).

Sementara itu menurut (Hyman & Sierra, 2010; 39) Penelitian deskriptif dapat menggambarkan lingkungan dengan mengidentifikasi karakteristik dari hal-hal atau fenomena yang berhubungan dengan satu sama lain, misalnya, jika laki-laki lebih mungkin dibandingkan perempuan untuk membeli produk tertentu, atau jika pembeli paling sering dari suatu produk tertentu yang lebih muda atau lebih tua.

Penelitian deskriptif digunakan ketika data statistik yang diperlukan pada fakta. Alat yang digunakan untuk melakukan penelitian deskriptif hampir selalu survei. Keuntungan dari survei adalah bahwa, jika jumlah orang yang disurvei (sampel) cukup besar, dapat dikatakan bahwa fakta telah terbukti dan benar dari seluruh kelompok ( Kolb, 2008; 25).

Referensi:

Hyman Michael R.  Sierra Jeremy J, 2010,  Marekting Research Kit for Dummies, by Wiley Publishing, Inc., Indianapolis, Indiana.

Kolb Bonita. 2008. Marketing Resear ch A Practical Appr oach: SAGE Publications Asia-Pacifi c Pte Ltd 33 Pekin Street #02-01 Far East Square: Singapore 048763.

Louis Cohen, Lawrence Manion and Keith Morrison; 2007 205), 270 Madison Avenue, New York, NY 10016. Sixth edition.

Mark R. Leary; 2001. Introduction to Behavioral Research Methods. THIRD EDITION: A Pearson Education Company. London.

Zikmund William,  Babin Barry J, Carr John C, Griffin Mitch; 2009. Business Research Method, Eight Edition.