Welcome back. We're continuing with our discussion of mobile data collection. We've talked about mobile web surveys ,and we'll now shift to a discussion of text message surveys, using texting or SMS to collect data, not just to invite or contact participants. So the first thing to really think about is that texting is ubiquitous. It's the primary method of daily communication in many parts of the world. Even the most basic mobile phones support texting. Billions of text messages are sent each month in the US and billions more globally, so it's at least worth exploring as a survey mode. As we've discussed for recruiting or contacting participants into data collection and other modes like web, including mobile web and telephone, but our focus now is on texting as a data collection mode, as an interview mode. So what do we mean by texting, because it's possible to interpret the term differently? Sending and receiving character-based messages limited to 160 characters in SMS, or short messaging service, or in Internet-based app the number of characters is unlimited. Both of those are within scope for the current purposes. These text messages are created either with an alphanumeric keyboard or keypad which generally requires pressing the same key multiple times to produce different letters. Versus virtual alphabetic keypads, which are more common on smartphones, so they're on-screen keypads with all alphabetic characters available. The messages are either displayed individually or they're threaded in the case of smartphones. So when they're threaded, the entire kind of history, the conversational history, is visible. When just individual messages are available in older cell phones, it's harder to reconstruct the history. And the arrival of a message generally alerts the user via a tone or a vibration or some kind of visual notification that the message has arrived. It kind of grabs their attention. This is one of the potential advantages of texting for survey data collection, is that even when one isn't particularly thinking about being a survey participant, the arrival of a message may well grab the respondent's attention. And then finally, texting may require the sender and recipient to subscribe to a service, such as WhatsApp. But because texting is native to virtually every mobile phone, much text communication can occur without any subscription services involved. This table kind of lays out the attributes of texting in comparison to the attributes of voice communication. So if we think about survey data collection, this would be telephone surveys, telephone interviews, versus text-based interviews. But really, these features apply to these media in general. And I won't go through the entire table, I'll just mention a few of the features in the table. So the first is synchrony. So the idea is that voice is fully synchronous. That is, when a speaker asks, say, a question or produces some speech, it's really expected that the listener will produce some speech almost immediately, often within a second. With texting, it's much less synchronous. While there can be that kind of rapid back and forth communication in texting, quite common for the response to be sent when the user has a moment, has time, when it's convenient. There just isn't the same expectation for an immediate response in text that there is in voice. Another feature that differs between voice and text is the conversational structure. So spoken communication occurs turn by turn. That is, that one person speaks, and then the person who was the listener becomes the speaker. [COUGH] And it works quite well, but there are occasionally errors in which the participants get kind of tripped up and they speak at the same time. But it's pretty rare and there are remarkably good mechanisms in place to overcome simultaneous speech. In texting, well, it is also turn by turn. Each message is a turn. There really is no analogue to simultaneous speech in texting, although occasionally text message may arrive out of order, out of sequence, but that's pretty rare. So while they're both turn by turn, the idea of stepping on the other person's toes is pretty unlikely in texting. Another feature that really distinguishes texting and voice communication is persistence. So texting is persistent. That is, one sends a text message and because it's visual it doesn't go away unless the user deletes it. It remains on the user's phone. It also remains in the cloud, but that's a separate issue. In voice communication the turns are ephemeral. They go away once they're uttered. Unless they're audio recorded, there's no record of what has been said. So that's a big difference. You can imagine that that might affect people's willingness to provide sensitive information. They might be reluctant to provide sensitive information if there's a permanent record. And another distinction between the two ways of communicating has to do with nonverbal cues, such as what are sometimes called paralinguistic features, like ums and uhs. With voice, ums and uhs just come with the territory. It's rich with respect to these paralinguistic cues. With texting there's virtually none of this unless somebody intentionally includes it. So you can type into a text message, to communicate perhaps, uncertainty about the rest of the message. But short of that, there's virtually no analogue to paralinguistic forms of speech. And then a final attribute that's quite different between voice and texting is the way multitasking occurs. So there are types of multitasking with voice and text, but they're different. So with voice it tends to be simultaneous, so one might be speaking on the phone while cooking, kind of doing the two things in parallel. At some deep internal level shifting between the tasks, but really engaging in the two tasks at the same time. But with texting it's pretty unlikely that one is both entering text into a text message and doing another task. But once a text message is sent, it's completely normal to switch to another task between the time the text message is sent and the time the user reads the reply to that text message. So all kinds of, the rest of life takes place between text messages. So it's really a task switching approach versus a simultaneous multitasking with voice. So these are a number of differences, and there are others in this table, that could lead to differences between the data, and particularly the data quality, collected with text and voice. So we'll turn shortly to evidence about measurement quality in text versus voice. But before doing that, let's talk about coverage and coverage error in text interviews because if the people who text are different from the people who don't text, then we have the same kind of problem we've discussed with web access in general. So the idea is that, of course, people who are not mobile phone owners are not likely to be texters. But it could well be that among mobile phone owners, those who do not text are different on some of the attributes we might want to measure in a survey than those who do text. But we just don't know. So a first investigation of coverage error is reported in an in-press chapter by Conrad and colleagues in which the authors looked at results from a telephone survey conducted by the Pew Organization in which they asked, among other things, whether they were mobile phone owners, and if they were, they asked them if they texted. And the survey also produced demographic data for these respondents, ao we can see if those mobile phone owners who text differ demographically from those mobile phone owners who do not text. And in the table here you can see that the demographic variables produced by this survey are age, sex, education, race, ethnicity, and income. And if you look under the column A for mobile phone owners and compare that to the values in column B for mobile phone owners who text, you can see that there are a few differences, but not many. There are differences in age, so fewer mobile phone owners who text are older than 34 years old. In other words, texters are younger than non-texters and there are slightly more college graduates, significantly but slightly, more college graduates among mobile phone owners who text than those who don't text. But other than that, there are no differences on the other attributes. And so the question is whether these two differences are likely to affect the answers that are collected in a survey that's conducted via texting. Another thing to consider is that the proportion of texters among mobile phone owners is growing, and that as it grows, any bias, in terms, for example, of age and education, is likely to be reduced. Also from Pew, texting rates among US mobile phone owners have been on the rise and are continuing to rise. So if we were to project where texting by mobile phone owners is going, we can see that we're approaching full coverage and that there may be no difference between mobile phone owners who text and those who don't. So we'll turn next to a discussion of measurement in text message surveys, focusing on a laboratory experiment that compares text and voice data collection. I'll see you in just a minute.
