With the advancement of computers and access to the Internet, surveys using the web are becoming increasingly popular. Such surveys save money by eliminating postage costs and save time by providing immediate access to returned surveys and improved data processing. This primer describes some considerations and suggestions related to the use of web surveys. In addition to issues of sampling error, question writing, and question sequencing, successful use of web surveys requires determining if a web survey is appropriate, determining the desired level of security and confidentiality, selecting design options that enhance the survey, conducting rigorous pilot testing, and implementing strategies to maximize response rate. J Allied Health 2008; 37:180-186. SURVEY RESEARCH is a frequently used methodology. With the advancement of computer hardware, software, and increasing access to the Internet,1 survey implementation using the World Wide Web (web) is becoming increasingly popular.2 After the necessary hardware and software is acquired, a web survey saves money3 by eliminating postage costs and saves time3 because the survey is immediately available to respondents after it is posted to the Internet and returned surveys are immediately available to the investigators. Additional time savings are realized because data processing is faster with web surveys.

While web surveys offer several advantages, they are not appropriate for every situation. Web surveys add a layer of technology not present in traditional paper surveys and have unique considerations related to design, pilot testing, and response rate. The purposes of this primer are to describe questions to consider when deciding if a web survey is appropriate, issues related to security and confidentiality, and the unique considerations related to design, pilot testing, and response rate inherent in web surveys. Issues related to sampling error, question writing, and question sequencing are beyond the scope of this report; publications addressing these issues are available.4-8

Determining if a Web Survey Is Appropriate

To determine if a web survey is appropriate, the investigators must first answer these questions: "Will the potential respondents have adequate Internet access?" and "Are the potential respondents computer literater2 In 2003, approximately 54% of United States households had Internet access.9 Access was not consistent across groups of people. For example, individuals with lower incomes, individuals with less education, and individuals with disabilities may have less home Internet access.10 In contrast, groups of people such as individuals in business, faculty members, and college students typically have access to the Internet.4

Knowing the potential respondents are likely to have Internet access does not address the adequacy of their access. Because some web survey design elements such as graphics increase download times,11 potential respondents with slower Internet service (i.e., dial-up modems) may become frustrated when attempting to complete a web survey. While broadband Internet service is faster and mitigates concern about download times, access to broadband Internet service is not consistent across the United States. In 2003, approximately 20% of households had broadband access, with less penetration of broadband in rural as compared with urban areas.12 Although limited to one state, a more recent example highlights the continued disparity in Internet access between urban and rural areas. In communities with < 15,000 households, wireline broadband access was 61% compared with 93% in three cities in Missouri (St. Louis, Kansas City, and Springfield).13

If potential respondents do have adequate Internet access, then the second question is "Are the potential respondents computer literate?"2 Computer literacy requires computer skills to access and navigate through the web survey.14 Knowledge of how to use computers, access Internet web sites, and complete web surveys will vary across people. For example, Schleyer and Forrest15 reported that a small number of dental professionals did not know how to return a web survey electronically and instead completed a paper copy of the survey and returned it by fax. Because of the variability in computer literacy, we believe potential web survey respondents should be given the telephone and e-mail contact information for questions related to the survey. Providing both types of contact information ensures that potential respondents with less computer literacy can contact the investigator.

Security and Confidentiality

An important consideration in using web surveys is determining the need for data security and confidentiality (Wolpin S: Personal communication to TM Austin, 20 July 2007).16 Collaboration among the investigators, web survey software providers, and individuals from information technology units at the investigator's institution should occur to ensure the desired level of confidentiality is achieved. Investigators should also ensure that stored data is protected. Examples of data protection may include physical and technical barriers to data access. For example, locked office suites represent physical barriers and computer passwords are technical barriers. Investigators should also establish mechanisms for data recovery in the event of an unforeseen loss of data (Wolpin S: pers. comm.).16

Deciding Among Design Options

Having decided a web survey is appropriate, the focus shifts to survey design. The sheer number of design options available to the web survey designer is a strength and a curse of web surveys. Understanding how design choices influence survey responses maximizes the likelihood of obtaining data that can be used to answer the research question.11,17 Examples of design choices include the following: choosing a question presentation style, displaying one question versus several questions per computer screen, using or not using a progress indicator, using radio buttons versus drop-down lists response formats, checking all that apply in a list versus responding yes or no to each choice, and forcing an answer to all questions versus allowing potential respondents to not answer questions. Each of these is addressed below.

There are multiple ways to present a web survey. One way is to present the web survey on a series of computer screens. With this approach, the respondent does not see the entire survey at once. One screen with one or more questions is delivered, the questions are viewed by the respondent, and responses are submitted to the server before the next computer screen is available.18 These steps are repeated until the survey is completed. This approach, called the interactive or paging approach,18,19 requires repeated contact between the respondent's computer and server hosting the survey and repeated submission of survey responses by the respondent. Using an interactive approach permits the possibility of automatic question routing within the survey. Because routing is controlled by the survey software, relying on the respondent to correctly follow routing directions is eliminated. Because survey responses are repeatedly submitted, investigators can determine how many respondents started but then abandoned the survey.18 For example, a respondent may submit responses to questions on the first two computer screens and then stop. With an interactive approach, the investigator knows the number of people who started but never finished the survey.

Because an interactive approach can deliver one or multiple questions per screen, the web survey designer has to choose which option to use. If the survey questions are related, multiple questions per screen may be appropriate. For example, a scale with four items measuring a construct such as pain could be presented one item per screen or on a single screen. Because the items are related to the same construct, presenting them on a single screen may be beneficial. Couper et al.18 reported that multiple related items on the same screen were completed faster, had less missing data, and had better interitem correlations than single items presented on multiple computer screens.

An alternative to the interactive approach is the scrolling approach.18,19 This approach delivers the entire survey at once. Assuming respondents do not have to answer a survey question to proceed to the next question, they can use the computer mouse to scroll forward or backward through the web survey, similar to paging forward and backward through a paper survey. Dillman4 recommends this approach because the presentation is similar to a paper survey. Routing is possible with the scrolling approach but relies on respondents correctly following routing instructions. The routing instructions can be text based, indicating which question to proceed to, or can be hyperlinked, requiring only a mouse click to move to the appropriate question within the survey. Respondents may not initially understand how to use hyperlinks. Peytchev et al.19 reported that college students were more likely to use hyperlinks that appeared later in the survey, indicating a possible learning effect for using these links. Furthermore, Peytchev et al.19 found limited evidence that hyperlinks for routing may have encouraged respondents to skip items.

Because the scrolling approach delivers the entire survey at one time and survey responses are not repeatedly submitted, potential respondents could begin answering questions but then abandon the survey without submitting any of their responses. In this case, investigators would not have information on the number of respondents who started but then abandoned the survey.18 Finally, using the scrolling approach with a long or graphic-intensive survey may be problematic as this may result in increased download time because the entire survey has to be downloaded before any questions can be completed. The choice between an interactive and a scrolling approach is not necessarily a dichotomy; rather, Peytchev et al.19 describe this choice as a continuum because it is possible to use features of both the interactive and scrolling approach to present a survey. For example, rather than either requiring a submission after each question or delivering the entire survey at once, large sections of the survey could be delivered, allowing the respondent to scroll through all of the questions in an individual section, submit the responses, and then receive the questions for the next section.19 Using this approach, Peytchev et al.19 were able to collect data on abandonment for each of the survey sections.

When choosing the web survey presentation approach, investigators have to decide whether data on abandonment should be collected, whether routing should occur automatically or with instructions, and whether it is important that respondents can view the entire survey at one time. There is likely no single web survey presentation approach suitable for all applications.19

Web survey software often has the option to include a progress indicator with the survey. Progress indicators give respondents an indication of how much of the survey remains to be completed as they answer questions. Progress indicators are not necessary if a scrolling approach is used because respondents can scroll through the survey to see how many items remain.4 Couper et al.18 reported that use of a progress indicator marginally reduced abandonment but increased download time. The increase in download time may have diminished the positive effects the progress indicator had on abandonment. In some cases, a progress indicator may be misleading. For example, when a survey includes both multiple-choice and short- answer questions, a progress indicator showing the percentage of the survey completed may mislead the respondent because these types of questions will vary in the length of time to complete.20

Web survey software programs provide several response option formats. Two that have been studied include radio buttons and drop- down boxes. Each of these has strengths and weaknesses. Dillman4 recommends using response options that most closely resemble traditional paper surveys. Radio buttons, which respondents use by clicking on the button with a mouse to indicate their choice, meet this recommendation because the process is similar to marking a circle to indicate a choice on a paper survey. Another alternative unique to web surveys is drop-down boxes. There are at least two types of drop-down boxes.17 One type of drop-down box initially displays one or more response options and requires a mouse click and scrolling to display the remaining options. The second type of drop- down box displays instructional text such as "click here" and requires a mouse click with potential scrolling to display all the options. Because the computer mouse can be used to scroll through the survey and through drop-down box response options, respondents may inadvertently change their answer in a drop-down box when they meant to scroll to the next survey question.