Continuous and time-sample measures of the in-seat behavior of a secretary were obtained. Measurement error, i.e., the extent to which the sample measures deviated from the continuous measure, was a function of the frequency of the sample measurements and the criterion used to score an example of the behavior.

A person manufactured his in-seat behavior for 15, 30-min sessions so that there were three blocks of five sessions where the behavior occurred 20%, 50%, and 80% of the time. Whole interval, partial interval, and momentary time-sample measures of the behavior were taken and compared to the continuous measure of the behavior i.e., per cent of time the behavior occurred. For interval time sampling, the difference between the continuous and sample measures i.e., measurement error, was: (1) extensive, (2) unidirectional, (3) a function of the time per response, and (4) inconsistent across changes in the continuous measure. A procedural analysis demonstrated that the frequency and duration of behavior are confounded in interval time sampling. Momentary time sampling was found to be superior to interval time sampling in estimating the duration a behavior occurs.

To identify potential sources and accumulation features concentrations, profiles, and patterns of polychlorinated naphthalene (PCN) residues were determined in sediment, mussel, crab, plankton, and fishes from the Gdan ˜sk Basin, Baltic Sea. Different marine organisms of the lower food web clearly bioaccumulate many PCN congeners. Depending on the matrix type, PCNs substituted with four or five chlorines dominate. Due to the characteristic profile and pattern of PCN congener groups found in subsurface plankton, mussel, and surface sediments, deposition from the atmosphere is postulated to be the main source of these pollutants. Nineteen of 22 tetra-, all 14 penta-, 9 of 10 hexa-, and both hepta-CNs could be quantified in the samples. The patterns of tetra-, penta-, and hexa-CNs varied largely between the samples or groups of the samples as well as when compared to the technical PCNs formulation Halowax 1014. This implies different absorption/retention rates and/or marked, structure-dependent metabolism of some PCN congeners by marine species.

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