Error control process

As identified by Visser et al. (2000) and Zikmund (2010), several types of errors can

occur in the survey processes. These errors can be divided into four types: sampling

errors or coverage errors, respondent errors and measurement errors. The sampling or

coverage errors occur when the sample does not properly represent the target population

This can occur due to economic reasons, such as not considering the whole population

from which to select the sample, or the results obtained from the survey can be biased to

one section of the sample (Hair et al. 2011; Zikmund 2010). Sampling errors or

coverage errors were minimised in the stage one survey, as the whole population was

included in the survey. To establish the correct contact details of the respondents, the

latest version of the directory was used. Therefore, all the information regarding the

respondents was up-to-date. The in-person interview sample was selected using the data

received from the stage one survey. Further, when selecting the prospective

respondents, their work experience, job purview and their authority to represent the

organisation were also considered. These steps helped to minimise sampling or

coverage errors.

Non-response errors are very common in mail surveys, however these can also occur in

in-person interviews due to several reasons, for example, the prospective respondent

refuses to participate in the survey, or the appropriate respondent is not selected for the

survey, or due to physical factors, such as the respondent is unable to respond to the

mail questionnaire (Hair et al. 2011; Zikmund 2010). In order to minimise non-response

errors with the mail survey and prior to contacting prospective respondents for in-

explained the objectives and the importance of the respondents‟ contribution to the surveys, which enhanced the response rate by reducing anxiety. To reduce the risk of

mail being lost, all the mail and the advance letters were posted from Sri Lanka.

Furthermore, each package included a postage-paid self-addressed envelope in order to

improve the response rate. The option of email was also offered so the respondents

could return their responses electronically if they so wished. This minimised non-

response errors, as the respondents were made to feel that they were given an easy

option to respond.

As a strategy to minimise non-response errors in in-person interviews, each respondent

was offered the findings of the stage one survey . Furthermore, during the confirmatory

telephone conversation, each respondent‟s agreement to participate in the interview was sought and if they required any clarification regarding the interview this was provided

prior to the interview. To deter any early termination, verbal and non-verbal

encouragements, as explained in the administration process were used. According to

Franke and Franke (1977), individual response bias errors occur when the respondent

knowingly provides incorrect information. This error was minimised by enlisting the

most suitable respondents for the survey (Krosnick 1999). During the in-person

interview at the beginning of Section G, respondents were informed that the interview

was close to completion to retain respondents‟ attention. Duffy et al. (2005) explain that in-person interview respondents are more susceptible to social bias due to the presence

of an interviewer. To minimise the social bias in the responses, every respondent was

informed that there was no right or wrong answer and only their perceptions were

considered (Duffy et al. 2005). Furthermore, respondents were informed by the

respondents. This was to make them more comfortable in explaining their experience

(Leigh, Claude and Martin 1987).

The non-response error can occur due to measurement errors in the mail survey and the

in-person interview questionnaire (Visser, Krosnick and Lavrakas 2000). Measurement

errors can occur due to formatting and administration issues in questionnaires (Phillips

1981). To minimise formatting errors in questionnaires, steps were taken to reduce

ambiguity and enhance the clarity of the questions (De Vaus 2002). As mentioned under

questionnaire development (section 4.4.3), several types of unsuitable questions were

not included in the questionnaires. All the instructions given in the questionnaires were

kept clear and uniformly simple. Furthermore, to minimise memory error during the in-

person interview, response cards were given to respondents (Oishi 2003). The questions

were properly pronounced by the interviewer during the in-person interview and several

probing techniques, as mentioned in the in-person interview administering section

(section 4.4.8), were used to enhance the quality of answers and to avoid early

termination. To ensure interviewer alertness during the interview, only two interviews

were scheduled per day to minimise any error due to interviewer fatigue.

In the mail survey, non-response bias was analysed with the aim of assessing the

generalisability of the sample population (Armstrong & Overton, 1977). Ideally, the

strongest test of non-response bias was to contact non-respondents and compare the data

from them. However, this option could not be performed due to financial constraints. As

a result, non-response bias was dealt with by comparing early respondents with late

respondents. As proposed by Armstrong and Overton (1977), this method is based on an

respondents. That is, some prospective respondents are too busy, or uneasy about filling

in a survey. Accordingly, comparison between early and late respondents reveals that

there are no significant differences on key demographic variables (Appendix O-Item A).

4.7

Summary

This chapter explained the reasons for the selection of the two stage data gathering . The

mail survey was selected as it was more suitable for an exploratory study and the in-

person interview was selected to provide an in-depth component to data gathering . For

the stage one mail survey, the total population (84 senior managers) representing global

container lines and their agencies were selected. Based on the responses received from

them, 36 senior managers were selected for the stage two in-person interviews

representing four types of strategic co-operations. The detailed process of developing

questionnaires to suit the selected data gathering methods and the processes adopted to

pre-test these questionnaires were also discussed in this chapter. In addition, this chapter

has discussed the questionnaire administration and error control processes adopted by

the researcher to enhance the data quality. The next chapter discusses the findings of the

stage one mail survey followed by an analysis of findings of the interviews in Chapter

Six.

CHAPTER FIVE

RESOURCES IN CONTAINER LINES

Chapter 5: Resources in container lines