“You don’t have to eat the whole ox to know that the meat is tough.”

Samuel Johnson
Data collecting instruments
The choice of data collection instrument is crucial to the success of the survey. When determining an appropriate data collection method, many factors need to be taken into account, including complexity or sensitivity of the topic, response rate required, time or money available for the survey and the population that is to be targeted. Some of the most common data collection methods are described in the following sections.

1.         Interviewer enumerated surveys
Interviewer enumerated surveys involve a trained interviewer going to the potential respondent, asking the questions and recording the responses.
The advantages of using this methodology are:
_ provides better data quality
_ special questioning techniques can be used
_ greater rapport established with the respondent
_ allows more complex issues to be included
_ produces higher response rates
_ more flexibility in explaining things to respondents
_ greater success in dealing with language problems
The disadvantages of using this methodology are:
_ expensive to conduct
_ training for interviewers is required
_ more intrusive for the respondent
_ interviewer bias may become a source of error

2.         Web surveys
Web surveys are increasingly popular, although care must be taken to avoid sample selection
bias and multiple responses from an individual.
The advantages of this methodology are:
_ cheap to administer
_ private and confidential
_ easy to use conditional questions and to prompt if no response or inappropriate response.
_ can build in live checking.
_ can provide multiple language versions
The disadvantages of this methodology are:
_ respondent bias may become a source of error
_ not everyone has access to the internet
_ language and interface must be very simple
_ cannot build up a rapport with respondents
_ resolution of queries is difficult
_ only appropriate when straight forward data can be collected

3.         Mail surveys
Self-enumeration mail surveys are where the questionnaire is left with the respondent to complete.
The advantages of this methodology are:
_ cheaper to administer
_ more private and confidential
_ in some cases does not require interviewers
The disadvantages of this methodology are:
_ difficult to follow-up non-response
_ respondent bias may become a source of error
_ response rates are much lower
_ language must be very simple
_ problems with poor English and literacy skills
_ cannot build up a rapport with respondents
_ resolution of queries is difficult
_ only appropriate when straight forward data can be collected

4.         Telephone surveys
A telephone survey is the process where a potential respondent is phoned and asked the survey questions over the phone.
The advantages of this methodology are:
_ cheap to administer
_ convenient for interviewers and respondents
The disadvantages of this methodology are:
_ interviews easily terminated by respondent
_ cannot use prompt cards to provide alternatives for answers
_ burden placed on interviewers and respondents
_ biased sample through households with phones

5.         Diaries
Diaries can be used as a format for a survey. In these surveys respondents are directed to record the required information over a predetermined period in the diary, book or booklet supplied.
The advantages of this methodology are:
_ high quality and detailed data from the completed diaries
_ more private and confidential circumstances for the respondent
_ does not require interviewers
The disadvantages of this methodology are:
_ response rates are lower and the diaries are rarely completed well
_ language must be simple
_ can only include relatively simple concepts
_ cannot build up a rapport
_ cannot explain the purpose of survey items to respondents

6.         Ideas for increasing response rates
1. Provide reward
2. Systematic follow up
3. Keep it short.
4. Interesting topic.

7.         Archival data
Rather than collecting your own data, you may use some existing data. If you do, keep the
following points in mind.

Available information Is there sufficient documentation of the original research proposal for
which the data were collected? If not, there may be hidden problems in re-using the data.
Geographical area Are the data relevant to the geographical area you are studying? e.g., what
country, city, state or other area does the archive data cover?
Time period Are the data relevant to the time period you are studying? Does your research
area cover recent events, or is it historical or does it look at changes over a specified range
of time? Most data are at least a year old before they are released to the public.
Population What population do you wish to study? This can refer to a group or groups of
people, particular events, official records, etc. In addition you should consider whether
you will look at a specific sample or subset of people, events, records, etc.
Context Does the archival data contain the information relevant to your research area?