Design of the study

3. Design of the study

The project included an industry advisory group who participated in the development of the study’s design, the generation of the scale items, and the extensive pretesting of the questionnaires. In particu- lar, the methodology addressing the research ques- tions and testing the hypotheses consists of two Ž . primary segments: 1 a series of focus group inter- Ž . views and 2 a set of survey questionnaires sent to US purchasing managers and their non-US suppliers. 3.1. Focus group interÕiews Four focus group interviews, conducted in the early spring of 1997, engaged purchasing managers from US firms that purchase from non-US suppliers. A copy of the questioning route appears in Appendix A. Two of the focus group interviews were con- ducted with top-level purchasing managers who held the title of Director or Vice President; two additional focus group interviews were held with informants at the purchasing manager or buyer level within their firms, who had direct and frequent contact with a Ž . non-US supplier s . Thus, homogeneity within groups is based upon occupational status and level of re- Ž . sponsibility within an organization Krueger, 1988 . Between five and seven informants participated in each of the focus group interviews. These partici- pants represent a broad range of industries, including consumer products, aerospace, pharmaceuticals, con- struction equipment and foodstuffs. It is important to note, however, that the purpose of conducting focus group interviews, ‘‘is not to generalize but to deter- mine the range, and not to make statements about the population, but to provide insights about how people Ž . perceive a situation,’’ Krueger, 1988, p. 96 . The third focus group yielded very repetitive results, while the fourth focus group interview yielded no new information. At this point, the focus group Ž . interviews were discontinued Calder, 1977 . 3.2. SurÕey questionnaire Based on findings from the interviews and from an examination of existing literature, a survey ques- tionnaire was generated and extensively pretested in the early spring of 1997, to assess face validity Ž . Heeler and Ray, 1972 of the scale items. The pretest, administered to a total of 29 academics and practitioners over two successive rounds, modified any questions that appeared to be ambiguous or inappropriate. The participants’ final comments indi- cate that face validity exists, and that the questions appear to be appropriately and clearly worded 1 . A second, near-mirror-image questionnaire sent to non-US suppliers of the surveyed buyers allows the researcher to examine not only the perspectives of purchasing managers, but also the matched perspec- tives of their suppliers. Given the broad number of potential countries and languages of the supplier representatives to whom this second survey could have been forwarded, it was not viable to provide a translated supplier survey. However, both the focus group and pretest participants indicate that they are the customers of their suppliers, and unanimously agree that the supplier representatives whom they regularly deal with speak English fluently. The au- thor considered the use of a triadic methodology, which would have included a third survey forwarded to a domestic supplier. However, there was concern that this additional supplier survey would have re- sulted in an insufficient number of responses, where fewer purchasing firms would have been willing to participate, given the requirements of forwarding two rather than one supplier questionnaires. 3.2.1. The sample Both surveys were sent to the purchasing organi- Ž . zations of 1300 domestic US firms in the spring of 1997. This sample consists of members of the NAPM, participants in previous CAPS purchasing perfor- mance benchmarking studies, and participants in the 1997 CAPS-sponsored Executive Purchasing Roundtable. Respondents in the buying firms were asked to focus most of their responses to the survey questions on their relationship with a particular inter- national supplier, and were also asked to forward the second, near-mirror-image questionnaire to the cho- sen international supplier. Like the buyer survey, this second supplier questionnaire was returned directly to CAPS. The supplier was asked to specifically 1 A copy of the questionnaire is available from the author. consider the buyer’s firm when answering the survey questions. Dillman’s Total Design Method was used in order to minimize non-response. Thus, three complete mailings, plus one reminder postcard, were sent to non-respondents over a 7-week period. Both the buyer and supplier surveys were coded to ensure that only one survey was received from each potential firm, and to match the responses of the buyer–sup- plier dyad. The results from the focus group inter- views and the mail survey are presented next.

4. Results from the focus group interviews