The perils of straying from protocol: sampling bias and interviewer effects.
Fidelity to research protocol is critical. In a contingent valuation study in an informal urban settlement in Nairobi, Kenya, participants responded differently to the three trained interviewers. Interviewer effects were present during the survey pilot, then magnified at the start of the main survey...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2015-01-01
|
| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0118025 |
| _version_ | 1818584382109122560 |
|---|---|
| author | Carrie J Ngongo Kevin D Frick Allen W Hightower Florence Alice Mathingau Heather Burke Robert F Breiman |
| author_facet | Carrie J Ngongo Kevin D Frick Allen W Hightower Florence Alice Mathingau Heather Burke Robert F Breiman |
| author_sort | Carrie J Ngongo |
| collection | DOAJ |
| description | Fidelity to research protocol is critical. In a contingent valuation study in an informal urban settlement in Nairobi, Kenya, participants responded differently to the three trained interviewers. Interviewer effects were present during the survey pilot, then magnified at the start of the main survey after a seemingly slight adaptation of the survey sampling protocol allowed interviewers to speak with the "closest neighbor" in the event that no one was home at a selected household. This slight degree of interviewer choice led to inferred sampling bias. Multinomial logistic regression and post-estimation tests revealed that the three interviewers' samples differed significantly from one another according to six demographic characteristics. The two female interviewers were 2.8 and 7.7 times less likely to talk with respondents of low socio-economic status than the male interviewer. Systematic error renders it impossible to determine which of the survey responses might be "correct." This experience demonstrates why researchers must take care to strictly follow sampling protocols, consistently train interviewers, and monitor responses by interview to ensure similarity between interviewers' groups and produce unbiased estimates of the parameters of interest. |
| first_indexed | 2024-12-16T08:20:17Z |
| format | Article |
| id | doaj.art-9a027b740f664f8083feacd29f093bca |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-16T08:20:17Z |
| publishDate | 2015-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-9a027b740f664f8083feacd29f093bca2022-12-21T22:38:07ZengPublic Library of Science (PLoS)PLoS ONE1932-62032015-01-01102e011802510.1371/journal.pone.0118025The perils of straying from protocol: sampling bias and interviewer effects.Carrie J NgongoKevin D FrickAllen W HightowerFlorence Alice MathingauHeather BurkeRobert F BreimanFidelity to research protocol is critical. In a contingent valuation study in an informal urban settlement in Nairobi, Kenya, participants responded differently to the three trained interviewers. Interviewer effects were present during the survey pilot, then magnified at the start of the main survey after a seemingly slight adaptation of the survey sampling protocol allowed interviewers to speak with the "closest neighbor" in the event that no one was home at a selected household. This slight degree of interviewer choice led to inferred sampling bias. Multinomial logistic regression and post-estimation tests revealed that the three interviewers' samples differed significantly from one another according to six demographic characteristics. The two female interviewers were 2.8 and 7.7 times less likely to talk with respondents of low socio-economic status than the male interviewer. Systematic error renders it impossible to determine which of the survey responses might be "correct." This experience demonstrates why researchers must take care to strictly follow sampling protocols, consistently train interviewers, and monitor responses by interview to ensure similarity between interviewers' groups and produce unbiased estimates of the parameters of interest.https://doi.org/10.1371/journal.pone.0118025 |
| spellingShingle | Carrie J Ngongo Kevin D Frick Allen W Hightower Florence Alice Mathingau Heather Burke Robert F Breiman The perils of straying from protocol: sampling bias and interviewer effects. PLoS ONE |
| title | The perils of straying from protocol: sampling bias and interviewer effects. |
| title_full | The perils of straying from protocol: sampling bias and interviewer effects. |
| title_fullStr | The perils of straying from protocol: sampling bias and interviewer effects. |
| title_full_unstemmed | The perils of straying from protocol: sampling bias and interviewer effects. |
| title_short | The perils of straying from protocol: sampling bias and interviewer effects. |
| title_sort | perils of straying from protocol sampling bias and interviewer effects |
| url | https://doi.org/10.1371/journal.pone.0118025 |
| work_keys_str_mv | AT carriejngongo theperilsofstrayingfromprotocolsamplingbiasandinterviewereffects AT kevindfrick theperilsofstrayingfromprotocolsamplingbiasandinterviewereffects AT allenwhightower theperilsofstrayingfromprotocolsamplingbiasandinterviewereffects AT florencealicemathingau theperilsofstrayingfromprotocolsamplingbiasandinterviewereffects AT heatherburke theperilsofstrayingfromprotocolsamplingbiasandinterviewereffects AT robertfbreiman theperilsofstrayingfromprotocolsamplingbiasandinterviewereffects AT carriejngongo perilsofstrayingfromprotocolsamplingbiasandinterviewereffects AT kevindfrick perilsofstrayingfromprotocolsamplingbiasandinterviewereffects AT allenwhightower perilsofstrayingfromprotocolsamplingbiasandinterviewereffects AT florencealicemathingau perilsofstrayingfromprotocolsamplingbiasandinterviewereffects AT heatherburke perilsofstrayingfromprotocolsamplingbiasandinterviewereffects AT robertfbreiman perilsofstrayingfromprotocolsamplingbiasandinterviewereffects |