Learning By Asking: How Children Ask Questions To Achieve Efficient Search

Learning By Asking: How Children Ask Questions To Achieve Efficient Search Azzurra Ruggeri (a.ruggeri@berkeley.edu) Department of Psychology, University of California, Berkeley, USA Max Planck Institute for Human Development, Berlin, Germany Tania Lombrozo (lombrozo@berkeley.edu) Department of Psychology, University of California, Berkeley, USA Abstract One way to learn about the world is by asking questions. We investigate how children (n= 287, 7- to 11-year olds) and young adults (n=160 17- to 18-year olds) ask questions to identify the cause of an event. We find a developmental shift in children’s reliance on hypothesis-scanning questions (which test hypotheses directly) versus constraint-seeking questions (which reduce the space of hypotheses), but also that all age groups ask more constraint-seeking questions when hypothesis-scanning questions are unlikely to pay off: when the problem is difficult (Studies 1 and 2) or the solution is one among equally likely alternatives (Study 2). These findings are the first to demonstrate that even young children adapt their strategies for inquiry to increase the efficiency of information search. Keywords: information search, active learning, 20-questions game, cognitive development. Introduction Yesterday, a man was late for work. Why? In everyday life, we constantly encounter events that require explanation. An observation, such as a man being late for work, can prompt us to seek underlying causes, either out of curiosity or because our future actions depend on them. For example, if the man was late because there is a public transportation strike, we might do well to rethink our own travel plans. Although the process of generating and evaluating explanatory hypotheses plays a crucial role in learning and development (Lombrozo, 2006), little is known about how children test hypotheses by seeking novel information from knowledgeable informants, or how this ability changes over the course of development. In particular, how do children ask questions to arrive at the correct hypothesis? In this paper we investigate children’s ability to flexibly adapt the kinds of questions that they ask, and whether the way in which they do so is responsive to task characteristics that affect the efficiency of different strategies. Specifically, we investigate how children (7- to 8-year-olds and 9- to 11- year-olds) and young adults (17- to 18-year-olds) identify the cause of an event by asking yes-or-no questions. Building on a classic study by Mosher and Hornsby (1966), which used a task like the game of “20-questions,” we differentiate between constraint-seeking questions and hypothesis-scanning questions. Constraint-seeking questions attempt to reduce the space of the possible solutions by asking about features that could apply to multiple solutions (e.g., “Was the man late because of something related to his means of transport? ” or “Did something happen at home? ”). In contrast, hypothesis-scanning questions are tentative solutions (e.g., “Was he late because he missed the bus? ” or “Was he late because he overslept? ”). Mosher and Hornsby found a large developmental change from age 6 to age 11, which has since been replicated (e.g., Denney, 1975; Denney & Denney, 1973), with younger children overwhelmingly asking hypothesis-scanning questions, and constraint-seeking questions becoming more frequent in the course of development. Subsequent research using the 20-questions paradigm has found that different task features can influence children’s and adults’ reliance on constraint-seeking questions. For example, Siegler (1977) found that 13- and 14-year-old adolescents were strongly influenced by the order in which two isomorphic 20-questions problems were presented (see also Nelson, Divjak, Martignon, Gudmundsdottir, & Meder, 2013), and Ruggeri and Feufel (2013) found that describing objects at a basic level (e.g., “dog” as opposed to “retriever”) increased the proportion of constraint-seeking questions in all age groups, suggesting that the basic-level representations facilitated children’s ability to identify object-general features on which to base their questions. However, few studies have investigated children’s ability to adapt their search for information as a function of task features that influence the efficacy—as opposed to the ease of implementation—of different questions. One exception is Nelson et al. (2013), who found that 4 th grade children were reasonably effective at asking constraint-seeking questions that partitioned a space of alternatives into equal subgroups, especially when the statistics of the possible solutions matched those of the real world. While several factors seem to influence children’s general ability to ask constraint-seeking questions, it remains an open question whether their strategies for inquiry are responsive to the anticipated efficiency of a given strategy (i.e., constraint seeking versus hypothesis scanning) in the task at hand. One possibility is that children's strategies for inquiry, compared to those of young adults, are quite inflexible. If this is the case, young children will overwhelmingly rely on hypothesis-scanning questions and will do so regardless of how effective the strategy is for a given instantiation of the task. This possibility is broadly consistent with the findings to date that have used the 20- questions paradigm: hypothesis scanning appears to robustly