A common mistake in analysis of cluster randomized experiments is to ignore the effect of clustering and analyze the data as if each treatment group were a simple random sample. This typically leads to an overstatement of the precision of results and anticonservative conclusions about precision and statistical significance of treatment effects.…

The International Boiling Point Project is an online, collaborative project for students in grades 6-12 in which they investigate the impact of four factors (room temperature, elevation, volume of water and heating device) on the boiling point of water. A detailed procedure is provided for students in order to limit the number of variables…

Three experiments investigated changes from 15 to 30 months of age in children's (N = 114) mastery of relations between an object and an aperture, supporting surface, or form. When choosing between objects to insert into an aperture, older children selected objects of an appropriate size and shape, but younger children showed little selectivity.…

Inducing causal relationships from observations is a classic problem in scientific inference, statistics, and machine learning. It is also a central part of human learning, and a task that people perform remarkably well given its notorious difficulties. People can learn causal structure in various settings, from diverse forms of data: observations…

Single-prime negative priming refers to the phenomenon wherein repetition of a prime as the probe target results in delayed response. Sometimes this effect has been found to be contingent on participants' unawareness of the primes, and sometimes it has not. Further, sometimes this effect has been found to be eliminated when the prime could predict…

We report a series of investigations into the effects of common names, physical identity, and physical similarity on visual detection time. The effect of these factors on the capacity of the system processing the signals was also examined. We used a redundant targets design with separate testing of the target-distractor (single target),…

Over the last century many individuals with exceptional memory have been studied and tested in the laboratory. This article studies Chao Lu, who set a Guinness World Record by memorizing 67,890 decimals of pi. Chao Lu's superior self-paced memorization of digits is shown through analyses of study times and verbal reports to be mediated by mnemonic…

Adults, preschool children, and nonhuman primates detect and categorize food objects according to substance information, conveyed primarily by color and texture. In contrast, they perceive and categorize artifacts primarily by shape and rigidity. The present experiments investigated the origins of this distinction. Using a looking time procedure,…

In this paper, a procedure is presented that will allow (i) the power and (ii) the energy of a pulsed and tuneable TEA CO[subscript 2] laser to be optimized. This type of laser represents a significant improvement in performance and portability. Combining a pulse mode with a grating tuning facility, it enables us to scan the working wavelength…

Prosodic contrastive focus is used to attract the listener's attention to a specific part of the utterance. Mostly conceived of as auditory/acoustic, it also has visible correlates which have been shown to be perceived. This study aimed at analyzing auditory-visual perception of prosodic focus by elaborating a paradigm enabling an auditory-visual…

This study investigates the way in which speakers determine which aspects of an utterance to emphasize and how this affects the form of utterances. To do this, we ask whether the binding between emphasis and thematic roles persists between utterances. In one within-language (Dutch-Dutch) and three cross-linguistic (Dutch-English) structural…

Associative learning is critical to normal cognitive development in children. However, young adults typically outperform children on paired-associate tasks involving visual, verbal and spatial location stimuli. The present experiment investigated cross-modal odour-place associative memory in children (7-10 years) and young adults (18-24 years).…

Based on the testimony of others, children learn about a variety of figures that they never meet. We ask when and how they are able to differentiate between the historical figures that they learn about (e.g., Abraham Lincoln) and fantasy characters (e.g., Harry Potter). Experiment 1 showed that both younger (3- and 4-year-olds) and older children…

Despite the progress in technology since the time of Maria Montessori, the science curriculum has been pushed aside slowly as teachers' focus has shifted to literacy and mathematics. The Early Childhood classroom has grown complacent with miniature life cycle lessons and attractive puzzles; the time has come to return science to a critical…

This study experimentally tested the relationship between children's lexicon size and their ability to learn new words within the domain of color. We manipulated the size of 25 20-month-olds' color lexicons by training them with two, four, or six different color words over the course of eight training sessions. We subsequently tested children's…