%0 Generic %D 2015 %T Moving the lab home: validation of a web-based system for developmental studies %A Kim Scott %E Laura Schulz %X

Moving the lab home: validation of a web-based system for developmental studies

Many practical considerations affect the kinds of scientific questions typically pursued by developmental labs.  Sample size is limited by the resources involved in participant recruitment and outreach, which constrains investigations to phenomena expected to manifest in most children and generate large condition differences. Special populations and longitudinal designs are often avoided outside of historically specialized labs because of the resources involved in recruitment and testing.  These practical constraints limit our ability to establish small or graded effects and to learn about specific disorders, individual differences, and the effects of interventions. 

We present a novel online interface  for infant and child recruitment and testing to enable large-scale participation in developmental studies, analogous to the kind of participation enabled by Amazon Mechanical Turk in adult cognitive science.  While families complete a short, browser-based developmental study, webcam recording is conducted programmatically using a custom-written, freely available Javascript library which interfaces with Flash.

Initial tests of the online studies demonstrated that preferential looking is easily elicited and detected from a webcam recording (see Figure 1). Study 1 validated preferential looking measures by replicating Experiment 2 of Yuan & Fisher (2009), which found that 2-year-olds could store information about the syntactic structure of a novel verb—even before learning what the verb meant.  As in the original paper, two-year-olds who heard a novel transitive verb spent proportionately more of their time looking at two-participant events compared to those who heard an intransitive verb when asked to find the novel verb (interaction between transitivity and question type, p = 0.05; N = 48 2-year-olds tested either on either a computer-based, webcam-recorded protocol in the lab or an identical protocol online). 

Study 2 validated verbal response measures in preschoolers by replicating a study by Schulz, Bonawitz, & Griffiths (2007) which demonstrated that by age 4-5 preschoolers take into account both prior beliefs and statistical evidence in attributing causal power; however, statistical evidence was taken into account by younger children only for initially plausible relationships. 64 3-year-olds (aged 36 to 42 months) and 105 4-year-olds (aged 48 to 60 months) have participated in a storybook-based online causal reasoning study.  Their verbal responses are consistent with a qualitative replication of the age trend reported in Schulz et al. (2007) (see Figure 2).

Study 3 is a replication of work by Pasquini et al. (2007) on preschoolers’ sensitivity to informant accuracy in epistemic trust, further validating verbal response measures using video stimuli and a purely online population.  Study 4 uses a replication of Teglas et al. (2007) to investigate differences in looking time measures online and in the lab.

We believe that most methods currently used in behavioral developmental research – looking-time and preferential looking studies, forced choice questions, structured interviews, and reaching tasks – can be transferred to the online environment. By reducing practical constraints on research with young children, we do not simply make life easier for researchers: we can expand the scope of the questions asked and make it more possible to run the scientifically right study to answer a question of interest.