Dear Mr. Sabri T. S Ahmed

To measure the validity and reliability, you can employ the SPSS program through product moment correlation analysis. You may refer to the SPSS guidebook to analys it from the beginning of the input data, analyze, and end of analysis then interpret it. Validity test is done by comparing r count and r table values. if the calculated r value is greater than r table then the data is valid and vice versa, if the r count value is smaller than r table then the data is invalid. Reliability test is done by comparing the value of cronbach alpha with the condition that the minimum cronbach alphan value is 0.6. that is, if the cronbach alpha value obtained from the spss calculation is greater than 0.6, then it is concluded that the data is reliable, on the contrary if the cronbach alpha is smaller than 0.6 then it is unreliable.

Regards,

you can validate it by testing the consrtuct validity through a likert scale assessing the importance of each item in relation to the construct purported to be measured; those who are determined as irrelevant or not important should be deleted.

The validate of questions should be reliable, fair, sufficient,easy to understand and relevance.

Validation by giving it to expert in the field, reliability by using SPSS as mentioned above.

The questionnaire provides us objective means of collecting information about people’s beliefs, knowledge, attitude, and behavior. The designing questionnaire

which is worthwhile and generalizable is an art, and it requires careful planning. The usefulness of questionnaire lies in quantifying the findings of initial exploratory phase. It is not helpful in cases where subjects may withhold information due to some or other reasons such as ignorance or subjects may perceive stigmatizing as they may think they are being judged by others. Types of sampling for questionnaires for research are different according to the type of study of population. Sample should be sufficiently large and representative of the entire population. Opportunity/convenience sampling is used for canvassing a known group of participants. It is avoided where we wish to generalize results to a wider population. Random sampling is used for wider homogeneous population every 9thperson in contacted. All have an equal chance of selection. For much wider population stratified sampling is preferred where homogeneous groups are identified and the sample is drawn from groups. Cluster sampling is used for heterogeneous groups. In cases where are wish to select randomly but can contact only limited number of people, while quota sampling used for a different group of social class (Hindu, Muslims, etc.) age, gender, etc. A definite number of social class is included in the study. Moreover, subjects may tick at random to should be formally approved by specialists. Validity refers to accurately measuring what it claims to measure while reliability is an assessment of reproducibility and consistency of a measurement or instrument.

Validating a research tools is a very important procedure in research. This can be done in different ways. One of these ways is to expose the tool to expert referees in the field. In this case, you need to attach your aims and the research questions and so on. In this case, referees can provide you with some remarks regarding construct validity and content validity. Moreover, you can pilot out the research tool on a sample of the subjects that you will exclude them in your main study. Pilot study is an important step than can help you whether the questionnaire items can work appropriately for the sample of the study or not. In this way, you can rethink of them in terms of doing some modifications for some items, deleting some items, or adding some items and so on.