pilot study + content validity

Depends!

If you want validate a questionnaire you must guarantee the tendence on giving social and desirable answers. The validity of a questionnaire for measure aptitudes, opinions, or satisfactions may be influenced by the tendence from people to give desirable and the social anwers to questionnaire items. That tendence is specially strong wnhen the items refer embaracing or intimate issues, or when the truth answer threatens the confidence of the respondente. So, if posible you must avoid items of this type. So you can apply measures of trend in use social desirable answers. You can try to use the Edwards measure (1957) to correct the questionnaire answers or eliminate from the sample the respondents who have stongly that tendence. If you wants to run faster your work you can try to write more neutral items  and test them on a preliminar study.

I hope it was useful and good luck for your work

pilot study + content validity

Validation is a long term process. It is concerned with the degree to which a questionnaire reflects reality. It is also about the questionnaire actually measuring what it is designed to measure.

It is always good to use validated questions from literature - directly with respondents or try to adapt them. Validity is linked to good questionnaire design, (such as inputs from experienced researchers, piloting with experienced researchers as well as respondents). The sampling frame and methods need to be robust, with appropriate rationale and determinations of sample size and, if necessary power. 

Reliability is also an important consideration  the degree to which a questionnaire will produce the same result if administered again, or the test-retest concept. It is also a measure of the degree to which a questionnaire can reflect a true change. As indicated already, there are a number of different aspects to validity. The degree to which questions within an instrument agree with each other is internal validity i.e., that a subject will respond to similar questions in a similar way. It also affects the likelihood of producing false positives and false negatives. The ability to make generalizations about a population beyond that of the sample tested is external validity. The degree to which the instrument can identify a true positive is sensitivity, for example, accurately identify a person who does have a belief. Similar to sensitivity is specificity, this is the degree to which the instrument can identify a true negative, for example correctly identifying the people who do not have the belief. Sensitivity and specificity are the flip side from internal validity. Related to internal validity is statistical validity, and assesses whether the differences in the questionnaire results between groups can appropriately be subjected to statistical tests of significance. There is also Longitudinal validity: whether a questionnaire returns the same results in a given population over time, assuming all else remains equal and in a social consideration there is Linguistic validity: whether the wording of the questionnaire is understood in the same way by everyone who completes it. The latter has implications when translating questionnaires for different languages and cultures.

Importantly there is content, construct and criterion related validity to consider.

Content measures the degree to which the test items represent the domain of the trait or property being measured. In order to establish the content validity of a measuring instrument, the researcher must identify the overall content to be represented. Items must then be randomly chosen from this content that will accurately represent the information in all areas. By using this method the researcher should obtain a group of items which is representative of the content of the trait or property that is to be measured

Construct must be investigated whenever no criterion of content is accepted as entirely adequate to define the quality to be measured, construct here explains some aspect of human behavior, such as physical ability, intelligence, or introversion.

Criterion is concerned with detecting the presence or absence of one or more criteria considered to represent traits or constructs of interest. One of the easiest ways to test for criterion-related validity is to administer the instrument to a group that is known to exhibit the trait to be measured.If the researcher has developed quality items for the instrument, a culling process should leave only those items that will consistently measure the trait or construct being studied.

Validity is also linked to Reliability (of which there a a range of types). There are Retest, Alternative Forms, Split_Halves and Internal Consistency methods. The latter finds wide use in Education and Social Science questionnaires

After an exhaustive literature review on the topic you are researching you should select questions already accepted and published in scientific journals. This same questions were tested and for sure can be useful for your study. Although, not all questions will fit your variable set but can give you directions for new formulation. In any case, your tool must go through a test-pilot and you need to analyze all responses, specially if you are using likert-type scales that should be tested for reliability by verifying inter-correlation among the items.

Before publication? Questionnaires need to be pretested at planing level. 

Please go through the site below is a published article which describes each step and phase of a questionnaire validation

https://www.hindawi.com/journals/jtrans/2018/9309486/abs/

Follow steps as attached file