Interviews and mailed questionnaires for the evaluation of annoyance reactions

ENVIRONMENTAL

RESEARCH

Interviews

8,

166-170

(1974)

and Mailed Questionnaires for the Evaluation of Annoyance Reactions

STEFAN SORENSEN,RAGNAR RYLANDER, AND KENNETH BERGLUND Department Department

of

Environmental

of Environmental

Hygiene,

Hygiene,

The National Environment The Karolinska Institute,

Protection

Stockholm,

Board and Sweden

Received August 31, 1973

Several environmental agents such as noise and odors can cause annoyance reactions in the exposed populations. The annoyance reaction can be defined as a feeling of displeasure, associated with an agent or a condition which the individual realizes or believes has an adverse effect. In exposure during a single event the momentary reaction can be defined as an acute annoyance. When a collection of humans are exposed during a number of events for a longer time period, a certain number of them will experience chronic annoyance (Lindvall and Radford, 1972). In order to study the presence of annoyance reactions due to exposure to different environmental agents, it is necessary to proceed from subjectively expressed opinions. These are generally compiled by means of interviews. From a scientific point of view, such investigations correctly performed have shown themselves to render reproducible results and constitute a reliable tool to measure this type of exposure effect (Jonsson, 1963; Sorensen, 1970). Social survey evaluations concerning annoyance due to environmental agents are usually presented as general investigations on living conditions where the real purpose of the investigation is masked. In initial questions the respondent has an opportunity to spontaneously mention annoyance due to the specific agent. Direct questioning concerning the agent does not take place until the latter part of the interview, when it is mixed with questions on other agents in the environment. Questions are then asked on annoyance intensity and different types of activity disturbance associated with the exposure. The extent of annoyance reactions in exposed populations can be evaluated in different ways. An annoyance score can be constructed from a summary of several questions concerning activity disturbances, personal experience of annoyance, etc. In general investigations in which the mean reaction in a population is studied, the precision is equally good if the annoyance is evaluated with the grading built into the answer to the straightforward question “how much are you annoyed?” (Rylander et al., 1972). Certain methodological considerations are important in connection with social surveys. In order to prevent the respondent from consciously exaggerating or underestimating his annoyance, the reason for the investigation must be masked and questions of annoyance due to the specific stimuli questioned must be included in a battery of similar questions concerning other factors in the vicinity 166 Copyright All rights

@ 1974 by Academic of reproduction in any

Press, Inc. form reserved.

INTERVIEWS

AND

MAILED

QUESTIONNAIRES

167

(Jonsson, 1963). This means that the questionnaires generally are rather long and a considerable amount of time is spent in each interview. The costs to perform such investigations thus become considerable. As an alternative to the personal interviews, mailed questionnaires have been suggested. These are shorter and can be distributed and evaluated with considerably less effort and expense than the personal interview. General methodological problems associated with mailed questiomiaires have been reviewed earlier (Scott, 1961; Kish, 1965; Franzen and Lazarsfeld, 1945; Ellis, 1947; Hochstim, 1967). In comparison to the interview method, the mailed questionnaire has several drawbacks. The masking effect could be less pronounced as smaller number of questions are inchided in the questionnaire. Furthermore, the respondent cannot be prevented from acquiring help from other persons, such as family members, etc. when filling in the questionnaire. The influence of attitudes and neighbours in terms of communication and discussions of the questionnaire is then not controlled. Finally, the dropout is usually larger, a factor which could constitute a selection process in the random sample originally drawn for the investigation. NO systematic studies have been performed in which interviews and mailed questionnaires have been compared. The purpose of the present study was to compare the results from mailed questionnaires and personal interviews in assessing the extent of annoyance in communities exposed to different environmental agents. 1. MATERIAL

AND

METHODS

The investigation was performed in 5 urban areas exposed to aircraft noise (area M), odors from refineries (areas N and St), general air pollution with a high level of dust (area Sk) and in a control area where no particular environmental exposures were known to be present (area V) . In each investigation area the population was defined as all persons aged lS-75, living in the area for at least 1 year. From the populat+on registry a random sample of 100 persons was drawn for the interviews and 150-1000 for the mailed questionnaires. In 2 areas (Sk and V) mailed questionnaires of 2 different lengths were used. The investigation was performed in 3 phases. In the first, odor from oil refineries was studied in the areas St and N (Fall 1968). In the second phase, aircraft noise in area M was studied (Spring 1970)) and finally, in a third phase, the air pollution and traffic noise in areas V and Sk ( Spring 1971) . The interviews were masked as a general investigation concerning living conditions in the neighbourhood. The questionnaires used in the different areas were identical in structure and based upon the international standard for social survey questionnaires. The general procedures such as interviewing and follow-up of dropouts were identical in all areas. The interviews were performed by interviewers who were instructed concerning the questionnaires and had received practical training. The postal questionnaires were mailed simultaneously to all respondents and reminder letters were mailed 3 and 10 days after the initial questionnaire.

168

SijRENSEN,

RYLANDER

AND

BERGLUND

The mailed questions in the short form contained 24 questions referring to background factors and the annoyance experienced. The interview questionnaire contained 181 questions. 2.

RESULTS

2.1. Response Rate

The response rate in the different areas is illustrated in Table 1. It is seen in Table 1 that the response rate in the interviews was around 95%. A lower response rate-about 8.5%was achieved in the questionnaire investigation. It is also seen that the larger questionnaire with approximately the same number of questions as the interview showed a considerably smaller response rate than the smaller questionnaire. 2.2. Extent of Annoyance

The amount of annoyance was evaluated using a summary evaluation and the extension of annoyance was evaluated as the percent of “rather or/and very annoyed” by the various agents studied. The results from the different investigation areas are reported in Table 2. It is seen in Table 2 that the extent of annoyance reported in the area exposed to aircraft noise was largely similar whether the interview or the questionnaire technique was used. In areas exposed to traffic noise, a greater extent of annoyance was found in the results from the interview technique. Those differences were not, however, statistically significant. Concerning annoyance due to particulate air pollution from industry and traffic, a slightly greater extent of annoyance was found with the questionnaire method in 3 out of 5 areas, where a significant extent of annoyance was reported. The differences were not statistically significant. When odor from industry was evaluated, the interview technique gave a considerably larger extent of annoyance in 2 of the areas studied.

SAMPLES

AND

RESPONSE

RATE

TABLE 1 IN DIFFXRENT

INVESTIGATION

AREAS

Questionnaire Short

Interview

Long

form

Response

Response Area

form

Response

Sample

(n)

(%)

Sample

(n)

98

700

651

93

-

-

-

95 95 98 91

1000 700 220 152

860 651 190 126

86 93 86 83

220 148

161 104

73 70

Sample

(n)

(%)

N

264

259

St M Sk v

105 110 150 150

100 105 147 137

(%)

INTERVIEWS

AND

MAILED

TABLE EXTENT OF ANNOYANCE (PERCENTAGE

IN

“RATHER

169

QUESTIONNAIRJS

2

DIFFERENT OR/AND

ARMS

EXPOSURE

VERY

ANNOYED”)

Questionnaire Agent/Area Noise, aircraft : M Noise, t,raffic: Sk v

Air pollution, N

1.

Odor, industry: 11’ St> Sk i

(Short) form)

(Long form)

18

30

li 17

IO 12

16 13

7 10 2 0

11 14 6 1

?i 0

6 7

6 5

s 6

15

1 :i I 1

4 0

industry:

St Sk v

Air pollution, Sk

Interview

traffic:

12 2 0

In the areas where no particulate air pollution or odor from industry present no significant annoyance was reported by either of the methods,

was

3. DISCUSSION

The methods used in the investigation to determine the extent of annoyance in communities exposed to different agents have been used on several other occasions. The present study further confirms that the methods are useful to determine the extent of annoyance toward agents in the environment. The results show that the size of the mailed questionnaire determined the response rate. Extensive mailed questionnaires as used in two of the areas resulted in a significantly larger nonresponse rate which reached proportions which invalidate the relevance of the results. In general, a response rate of above 90% is desirable to ensure that reliable results are obtained. If the interview and questionnaire methods are compared it is seen that differences existed in the extent of annoyance obtained with the two methods, which are related to the type of agent studied. Concerning aircraft noise and air pollution from traffic and industry, no extensive difference was found between the two methods. The results on traffic noise and odor from industry showed a higher annoyance rate for the interview method. The extent of annoyance in the questionnaires concerning these agents was on the average about 8% lower than in the interviews. The lower annoyance rate evaluated in the questionnaires was unexpected due to the methodological problems discussed earlier. The possibility for the

170

SikENSEN,

RYLANDER

AND

BERGLWND

test person to discuss the questionnaire and the possibility to consciously exaggerate the annoyance are apparently not causing an increase in the annoyance rate as compared to the interview technique. The reason for the fairly large difference in results on annoyance due to odors is not clear. One possible explanation is the time sequence of the exposure. Whereas noise or air pollution from traffic represents a relatively constant exposure in the environment, odor exposures often occur with intervals during short time periods. It is thus feasible that the test persons when filling in the questionnaires tend to forget or surpress the reaction towards odors, while in a more detailed, personal interview procedure, a more certain reaction can be evaluated. In conclusion, the results of a study are reported which demonstrates that mailed questionnaires can be used to evaluate the extent of annoyance toward agents in communities with the possible exception of odors. The method can thus provide a basis for exposure, limiting programs to be set up by health authorities. The slightly lower extent of annoyance with the questionnaire technique should be kept in mind when results from such investigations are compared to experience on annoyance reactions due to other agents evaluated with the interview technique. It must finally be emphasized that the execution of annoyance studies either as personal interviews or mailed questionnaires should be undertaken only by personnel with scientific training concerning the methodological problems involved. Common market survey analysis techniques and other types of simple questionnaire techniques can not be used in this context. REFERENCES A. ( 1947). Questionnaire versus interview methods in the study of human love relationship. Amer. Social. Reu. 12, 541-553. FRANZEN, P., AND LAZARSFELD, P. F. ( 1945). Mailed questionnaire as a research problemI. Physiol. 20, 293-320. HOCHSTIM, J. R. ( 1967). A critical comparison of three strategies of collection data from households. J. Amer. Statist. Assoc. 62, 97&989. JONSSON, E. (1963). Nuisance from external environmental factors and norms for their evaluation. No&. Hyg. Tidskr. 44, 69-84. Km, L. ( 1965 ) . “Survey Sampling” Wiley, New York. LINDVALL, T., AND F~ADFORD, E. P. (1973). Measurement of annoyance due to exposure to environmental factors. Environ. Res. 6, l-36. RYLANDER, R., SORENSEN, S., AND KAJLAND, A. ( 1972). Annoyance reactions from aircraft noise exposure. J. Sound Vibrat. 24, 419-444. SCOTT, C. ( 1961), Research on mail survey. J. Roy. Statist. Sot. 24, Ser. A, 143-205. S~~NSEN, S. ( 1970). On the possibilities of changing the annoyance reaction to noise by changing the attitudes to the source of annoyance. Nor& Hyg. Tidskr. Suppl. 1, l-76. ELLIS,