Posting your questionnaire online gives anyone connected to the Internet potential access to your survey. The potential imposter/repeater problem is well-known. By default, respondents may access a Lighthouse Studio survey as many times as they want. You can limit or control this by creating respondent identifiers within the Questionnaire Access window.
Unique IDs
You can require the respondents to have a single or multiple unique identifiers (Lighthouse Studio supports up to 255 characters per identifier). These are usually included in the URL sent to respondents, but can also be entered manually if the survey enables the Login question in the Questionnaire Access window. By default, any value can be used for identifiers. However, by clicking on Define IDs you may specify whether identifiers can come from external sources such as panel provider, or whether values are limited to those specified in the software.
If you are limiting the respondent identifiers, you can specify how many times each identifier combination may be used to access the survey. Most of the time, each combination is specified for single use (Max Respondents=1). This has two benefits: each respondent may only take the survey once, and if respondents return to an incomplete survey Lighthouse Studio can restart them at the point they left off. Restarting is not allowed for a combination where Max Respondents permitted is greater than 1 (unless you use cookies). Providing respondents with identifiers permits them to access just their survey; it does not give them access to other aspects of your Web server including the stored data.
You can use the Define IDs window to generate thousands or even millions of random identifiers, or you can import them (as well as Merged Fields) from text files.
Link Variables: It is common to pass in data to the survey on the URL link that respondents click to start the survey. For example, you might be launching a Lighthouse survey from a third-party application and want to pass-through the respondent identifier to be stored as well in the respondent's record in Lighthouse Studio. You define these 'Link Variables' within the questionnaire access window. The number of link variables is only limited by the constraints on length of URL strings imposed by browsers.
Merged Data: Sometimes you already have some respondent data prior to fielding a survey (such as descriptive data for online panelists) and you want this information to be available during the questionnaire to display certain prior-known information or to execute skip patterns. Lighthouse Studio lets you supply up to 250 Merged Fields (variables) in addition to identifiers that will be automatically merged into each respondent's record upon accessing the survey. Both the Identifiers and the Merged Fields are stored within the same database file.
Access Method: Most respondents receive links that include the identifiers in the URL. However, you can optionally add a login page to the survey where respondents will type in their identifier values. This can be useful when you want to provide a simple URL without complicated formatting.
Cookie-based restart: By default, we do not write cookies to respondents' local drives. However, you can turn cookies on and if respondents do not block them (through their browser configuration settings), they can be used to restart incomplete questionnaires. The cookie will also keep a respondent from completing more than one survey (unless, of course, the respondent disables the cookie). If you ask Lighthouse Studio to write cookies, they will be used when the respondent could not otherwise be uniquely identified by their identifier specified to start the survey (e.g. those with Max Respondent>1, or none specified at all).
For more information on Cookies, see Appendix H: Cookies.