K. H. Grobman

Research Interests

My research aims to bridge the "great divide" (Chen & Siegler, 2000) in the way problem solving is understood in infancy and later childhood. Specifically, I have designed a task to measure in infants the same problem solving strategies that are measured in older children and adults. In the sections that follow I will describe the Pull-Through-Angle task and demonstrate how my colleagues and I have used it to examine problem solving in relation to a range of individual differences and with respect to the role played by social context.

Domain General Problem Solving Strategies (Hill-Climbing & Means-Ends Analysis)

The Pull-Through-Angle task was designed to tease apart the use of hill-climbing and means-ends analysis by 9- to 16-month-old infants. In this task a toy is placed on a cloth that extends through the entire length of a canal. In one condition, the toy moves continuously closer to infants as they pull on the cloth. To solve this problem by hill-climbing, infants must notice that a small tug on the cloth moves the toy closer, and that continuing to pull the cloth reduces the difference between themselves and the goal. In a second condition, the toy moves further away before moving closer to infants as they pull the cloth. To solve this problem by means-ends analysis, infants must notice that in order to get the toy, they first need to get the cloth. Whereas the problem in the first condition may be solved by hill-climbing or means-ends analysis, the problem in the second condition is solvable only by means-ends analysis.

Results from the original Pull-Through-Angle study (Grobman & Gilmore, 2003a) revealed that 9-month-olds could not use either strategy and that 16-month-olds could use both. The 12-month-olds could use hill-climbing as well as the 16-month-olds, but were no better at using means-ends analysis than the 9-month-olds. After some experience with the task however, the 12-month-old infants were able to use means-ends analysis as well as the 16-month-old infants. Taken together, these findings suggest that domain general problem solving strategies develop gradually throughout infancy, and that means-ends analysis can be learned within some particular contexts.

Individual Differences (Motor Development & Working Memory)

In addition to studying their developmental origins, I have examined problem solving strategies in relation to motor development and working memory, individual differences likely to be associated with problem solving ability (e.g., Rabinowitz et al, 2002). Specifically, I have worked with Rick Gilmore (Grobman & Gilmore 2003c,b) to create measures of these individual differences and relate them to performance on the Pull-Through-Angle task.

Data from our parent survey on the onset of various motor milestones (e.g., crawling, walking) revealed patterns consistent with Gesell (1934): infants achieve motor milestones in a stage like progression. Further, a factor analysis revealed a single underlying component, suggesting that infants are rarely "late bloomers" for one milestone and "early bloomers" for another. Infants who achieved motor milestones earlier relative to their age mates, were more successful on the Pull-Through-Angle task.

Our data on working memory were collected with a 9-item measure that combines elicited-imitation and delayed-response, methodologies employed in standard infant memory tasks (e.g., Bauer et al, 1999; Diamond, 1995; Meltzoff, 1988; Reznick et al, 1998). Infants' performance on all nine items loaded positively onto the first principal component in a factor analysis, suggesting that our task measures a single underlying construct. We found that infants with greater working memory were more successful on the Pull-Through-Angle task, and slightly more likely to learn a new strategy over the task's 16 trials.

Social Cognition & Social Context (Help-Seeking, Scaffolding, & Modeling)

In considering the larger social context in which problem solving takes place, Ulrich Mueller and I tested Fajans'(1933) observation that when presented with a toy out of reach,10-month-old infants show higher levels of activity when a person approaches the toy. We examined group differences in help-seeking behavior among infants 6- to 18-months of age. Preliminary analyses suggest that older infants are better able to coordinate their help-seeking behaviors when presented with a toy out of reach, and that as a group, infants engage in more help-seeking behaviors when a person (as opposed to a control object) approaches the toy (Grobman & Mueller, 2003).

My colleagues and I (Grobman & Gilmore, 2003d) have also examined the influence of particular social learning opportunities on the development of problem solving. We varied 12-month-old infants' experience in the Pull-Through-Angle task by varying the instructions given to their parents. Parent-child dyads were assigned to one of three conditions: scaffolding, modeling, or control. Our findings support numerous observational accounts of learning (e.g., Hodapp et al., 1984; McNaughton and Leylan, 1990; Palinscar & Brown, 1984; Rogoff et al., 1984). Specifically, we found that infants in the scaffolding and modeling conditions were more successful on the Pull-Through-Angle task than infants in the control condition. Further, infants in the scaffolding condition showed a greater degree of strategy learning than infants in the modeling and control conditions.

Future Directions

Findings from the Pull-Through-Angle task have suggested that strategies can be learned through experience in a particular problem-solving context. In future studies, I plan to examine how experience with the conceptual underpinnings of the task (e.g., repeated exposure to the movement of objects on surfaces) might influence task performance. I also hope to extend to other tasks the basic finding that domain general problem solving strategies are acquired gradually. In an analogous Locomote-Through-Angle task for example, infants might crawl through a maze in order to reach their parents.

Given the absence of evidence for the learning of hill climbing in my studies, I have designed the "Almost-Rewarded" task to examine the possibility that hill-climbing is innate. The task uses operant conditioning to determine whether infants find getting closer to a goal (i.e., hill-climbing) as rewarding as achieving a goal. Finally, I plan to study infants longitudinally to examine how early problem-solving experiences shape children's later understanding and use of problem solving in a school environment.

References for Manuscripts in Preparation & Under Consideration

Grobman, K. H. & Gilmore, R. O. (2003a). The gradual emergence of domain-general problem solving strategies during infancy. Manuscript under revision for Child Development.

Grobman, K. H. & Gilmore, R. O. (2003b). Individual differences in infants' immediate-recall memory using elicited-imitation and delayed-response tasks. Manuscript in preparation.

Grobman, K. H. & Gilmore, R. O. (2003c). The structure of infants' motor milestones and its relationship with perceptual and problem-solving development. Manuscript in preparation.

Grobman, K. H. & Gilmore, R. O. (2003d). Scaffolding & modeling as causes of infants' problem solving development. Manuscript in preparation.

Grobman, K. H. & Mueller, U. (2003). Contextual factors influencing 6- to 18-month-old infants help-seeking strategies. Manuscript in preparation.