The Rasch model and additive conjoint measurement.

In this paper we clarify the relationship between the Rasch model, additive conjoint measurement, and Luce and Tukey's (1964) axiomatization of additive conjoint measurement. We prove a theorem which links the Rasch model with additive conjoint measurement.

The relationships among design experiments, invariant measurement scales, and domain theories.

In this paper we discuss principled design experiments, a rigorous, experimentally-oriented form of design-based research. We show the dependence of design experiments on invariant measurement scales. We discuss four kinds of invariance culminating in interpretive invariance, and how this in turn depends on increasingly adequate theories of a domain.

Haemoprotein- and transition metal ion-catalysed oxidation of linoleic acid. Selectivity of the position of oxygenation.

Oxidation of linoleic acid in aqueous buffers favoured the formation of the 13 positional isomers of hydroperoxylinoleic acid. The reaction which was catalysed by haemoproteins and Fe(II) and Cu(II) ions showed positional selectivity that was similar to lipoxygenase-catalysed reactions but yielded equal proportions of both enantiomers of the hydroperoxides. There was little selectivity when methyl linoleate was used as the substrate or when linoleic acid was oxidised in organic solvents.

The control of feeding behavior by an imprinted stimulus.

Imprinted ducklings were trained to peck a pole using brief presentations of the imprinted stimulus as the response-contingent (reinforcing) event. Subjects were then permitted to spend extended periods with continuous access to food and the imprinted stimulus (via a pole peck). For other (control) subjects the experimental situation was restricted to either responding for the stimulus, or feeding in the absence of the stimulus.