Central Location Testing: Still Golden In Its Golden Years

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Introduction

From the 1940s through the early 1970s, face-to-face interviewing in the United States was conducted largely by way of door-to-door interviews. As American women increasingly worked outside the home, door-to-door interviewing had to be conducted in the evening, when potential respondents were home. Due to safety concerns, interviewers were less willing to knock on doors at night, so in the early 1970s field services started renting space in shopping centers and putting small trailers in shopping center parking lots and, voila, a new era of data collection-central location testing-was born. Central location testing typically takes place in malls, but can also be conducted in supermarkets, convenience stores, and other retail outlets, and public places such as churches, community centers, and libraries.

In the last few years, with the explosion of online interviewing, central location testing (and, hence, face-to-face interviewing) has experienced a decline. However, central location testing is far from an antiquated technique; virtually all mall facilities have computer-assisted personal interviewing (CAPI), which provides many of the benefits of online interviewing such as speed, accuracy, and the ability to re-contact respondents with follow-up questions.

While online may still be faster and, in most cases, more cost-effective, there are certain situations where face-to-face interviewing is the only appropriate means of conducting marketing research. Specific sample requirements, certain types of research, and lengthy surveys are examples of when central location testing may be the preferred method of data collection in order to ensure optimal survey results.

Sampling and Special Targets

Mall intercept interviewing, where unsolicited participants are selected at random in busy regional shopping malls, is a common form of central location testing. Shoppers are intercepted, screened, and recruited to participate in the survey at hand. While interviewers sight-screen for age, gender, and ethnicity, the sample selected is reflective of a broad universe. And, with hundreds of mall test facilities across the country to choose from, good geographic representation can be obtained. Depending on the level of representation needed, studies can be conducted in just a few malls or in as many as 50 malls or more.

Mall intercepts provide access to a diverse respondent population. Because demographic information is known for hundreds of regional malls around the country, specific malls can be chosen that have a high percentage of Hispanic traffic, African-American traffic, higher income traffic, and the like, allowing convenient access to typically hard-to-reach subgroups.

Mall intercepts are also ideal for interviewing children and teenagers. Since permission must be obtained from a parent or guardian when interviewing children 12 or younger, mall interviewers can sight screen for adults who have children with them. (The screener is always asked of the adult.)

Mall intercept interviewing provides a robust source of respondents who are strong purchasers of all types of consumer products, and is not limited to high-incidence test categories. Low-incidence populations are routinely telephone pre-recruited using client lists or databanks compiled by the local field services.

Types of Research

Central location testing is often the best way to conduct a product test, either because of the type of product being tested or because of the design of the test. Central location testing is also ideal for qualitative research and pilot tests.

Product Tests

Type of Product Being Tested

While home usage is always an ideal means of testing products, especially those with long purchase cycles, certain types of products simply cannot be shipped to respondents' homes. Frozen foods, fragile products, and heavy products all require special shipping that would be cost-prohibitive to ship to individual private homes, especially with large sample sizes. Alcoholic beverages are almost always tested in central locations, where respondent age can be verified.

In addition, product tests may require extensive or precise preparation (baking cookies, for example) or demonstration (like for testing computer software). On-site interviewers trained on how to prepare and demonstrate test products can help ensure that they are presented to respondents correctly and consistently.

Product Test Design

Many product tests are sensory tests, meaning that respondents' reactions to the taste, feel, or scent of a product are evaluated. Common sensory tests are taste tests. In a typical taste test, respondents taste up to four flavors, rating each one overall and on a series of attributes. The flavors are rotated to control for both position effects and contextual effects (each flavor will be tasted just before or just after every other flavor about equally). Between each tasting, respondents eat a cracker and wait 30 seconds until tasting the next flavor. After all flavors have been tested, respondents rank the flavors from most to least preferred.

For sensory tests such as these, central location testing offers two key benefits over other data collection methods:

• Valid Measurement Often the best way to measure reactions to taste, touch, and scent is via immediate and direct observation. Face-to-face interviewing accomplishes this.
• Process Control With a trained interviewer leading each respondent through the necessary steps of a sensory test, central location testing provides superior control to in-home usage tests. Trained interviewers can guide respondents with rotations and restrictions (for example, Product A should not be tasted immediately before or after Product B because both are very spicy). Anytime three or more products are tested, central location testing should be considered.

Qualitative Research

Qualitative research is perhaps the most common form of research conducted in central locations. Central locations allow for interactivity among participants--including non-verbal cues--and are extremely conducive to brainstorming and ideation. A variety of stimuli can also be introduced in a live focus group, including concepts, products, store shelves, and videotapes.

Pilot Tests

Pilot tests should be conducted in central locations whenever possible. Whether verifying the validity of a multi-cultural survey or testing the viability of an especially difficult survey, central location pilot tests are invaluable for testing questionnaires and then immediately debriefing respondents. The feedback will be rich, insightful, and instantaneous.

Long and Difficult Interviews

Lengthy surveys are usually more suited to central location testing than other data collection methods. When respondents are presented with surveys that are 30 minutes or longer, they are less likely to complete them on their own than during a face-to-face interview. They are also more likely to think more about their responses in a face-to-face interview, rather than moving as fast as they can through a self-administered survey.

Extremely difficult surveys (for example, those requiring numerous picture or card sorts) are also better suited to face-to-face interviews since onsite interviewers can help respondents with the questionnaire instructions. Paper questionnaires may be more appropriate than online surveys if the survey instructions do not lend themselves to programming. For example, market structure studies are usually conducted face-to-face and with paper questionnaires. These studies, which produce perceptual structures of the market and brand landscapes, can take 40 minutes or longer to complete and may require the respondent to sort up to 150 SKUs or products (usually in the form of package photographs) into piles based on similarity of use.

Mall Intercepts: Additional Benefits

Mall interviews offer high quality research results because they follow stringent validation procedures that verify that respondents qualified for and completed the surveys. In addition, mall test facilities allow clients to directly observe interviewing through one-way mirrors. Further, because respondents are not given possession of the concepts being tested, malls provide greater confidentiality than other research methods. Finally, mall field services are not currently threatened by legislation that might narrow their ability to recruit respondents.

Challenges to Central Location Testing

While central location testing offers many benefits, it also faces several challenges. The popularity of discount merchandisers not anchored in malls and the advent of online shopping are reducing traffic in malls, making it more difficult to recruit respondents. Fortunately, declining mall traffic can be counteracted by pre-recruiting respondents to central locations through databases maintained by local field services.

A second challenge to central location testing is interviewer cheating. Tight quality control is necessary to thwart cheating, including choosing only reputable field services, visiting field services often to observe procedures, and strict enforcement and monitoring of post-interview validation.

Another challenge is that face-to-face interviewing can lead to biased responses. A respondent may have an exceptionally positive or negative response to the personality or image of the interviewer, leading to interview responses that are unfairly positive or negative. In addition, an interviewer may ask questions or react to responses in an influential manner, biasing the results. These biases can be offset by only using field services with well-trained interviewers and by maintaining consistency of field suppliers if mall data is being databased.

Summary of Benefits

As online research continues to grow, central location testing is still a relevant and valuable means of data collection. In some cases, central location testing is the only practical way to implement a survey and the best way to ensure high quality results.

Central location testing offers the key advantage of face-to-face interviewing, which is ideal for conducting many kinds of product tests as well as qualitative research and pilot tests. Central location testing can achieve higher response rates and better results in cases where there is an extremely long or difficult survey. Central location testing is conducive to finding special target samples, such as ethnic groups, children, and teens. Mall intercepts offer stringent validation procedures, allow clients to directly observe interviewing, provide greater confidentiality than other research methods, and will not be impeded by pending legislation that will narrow the ability to recruit respondents in other survey methodologies.