The purpose of this study was to perform a sequential analysis of private and social speech in children's dyadic communication. To investigate the communication patterns, a category system was applied to the communication of 64 paired third (M = 8 years and 8 months) and fifth (M = 10 years and 8 months) graders, while playing with a Lego-set (construction material). The results revealed that: (a) at both grades, when one child addresses the other child about the task, it is highly probable that the latter will address the first child immediately afterwards and will adapt to task-related semantic content; (b) at both grades, children's private speech about the task stops them from communicating a task-related production to their partner immediately afterwards; (c) at third grade, task-relevant private speech favors the prolongation of the break in interpersonal communication and the use of inner speech by both children; and (d) at fifth grade, children are more able to distinguish private speech from social speech than at third grade.

Three-hundred and twenty written accounts of environmental transgressors were assessed by sequential analysis to reveal their argument streams. The accounts were obtained from the written statements that transgressors are allowed to give during the Spanish administrative process and which were included in files handled by four environmental law enforcement agencies. These agencies are distributed across national, regional, island and municipality jurisdictions. The setting for the study is a highly protected environment in which environmental laws have high salience. Results reveal that transgressors use simple argument streams, consistently more defensive than conciliatory, and questioning the perceived legitimacy of environmental law. It was seen also that the empirical functioning of the explanations related to pursuing emotional/prosocial objectives differs from what was expected from the traditional conceptual definition. Results are discussed in terms of how the assessment of the internal dynamic of the accounts would provide valuable information on transgressors' reasoning in relation to environmental laws.

Aims – To study an analytical approach towards sequential analysis of the medical interview. An interview phase constitutes the analytical unit. Generally accepted phases of the medical interview are 1) medical history, 2) physical examination and 3) the conclusion segment. While descriptive and prescriptive studies claim that the sequence of the phasing is standard, it is hypothesised that in natural medical conversation the sequencing of the interview is more complex. For the doctor, the sequencing pattern is a powerful device to structure the interview and to manage the interactions within a limited time span. For the patient, especially the conclusion segment will contain more self-selection than other segments. Key concepts are turn taking, topic shift, topic flow, conversational coherence and responsiveness. Methods – The data consisted of 800 verbatim transcript pages of 85 medical interviews obtained from general practice. Interplay of theoretical notions and data-driven observations produced a reliable analytical method described in the article. The method enables to study processes of (a)symmetry in medical communication and the ways to deal with problems of misunderstanding. Results – Results confirmed 1) the asymmetrical character of the interview, 2) the complexity of the phasing, and 3) the existence of several types of interviews. Conclusions – The method can be applied for a broad range of research questions.

Declaration of Interest: none.

Aims – The aim of this small scale study was to explore interaction sequences during the medical consultation. Specific attention was paid to how doctors responded to patient's concerns and worries. Empathic behaviours ( e.g. concern, partnership, legitimising) and facilitating behaviours (e.g. paraphrasing, agreement) were considered as an adequate response to a patient's concern. Methods – Nine consultations of nine different GPs were randomly selected from a sample of 1600 videotaped doctor-patient consultations, that were all rated with the Roter Interaction Analysis System. Each consultation contained at least 9 utterances of patient's concern. It was investigated how doctors respond within five lags of utterances after a patient's concern. Results – The results showed that doctors more often responded to a patient's concern in a facilitative way than in an empathic way. When an empathic response was given, it appeared mostly during the first utterance after the patient expressed a concern. Conclusions – The findings indicate that sequential analysis is appropriate to investigate a health care provider's specific style of responding. Based on the problems emerged during the sequential analysis, further exploration of the method is recommended.

Declaration of Interest: none.

The first passage time of a random walk to a barrier (constant or concave) is of great importance in many areas, such as insurance, finance, and sequential analysis. Here, we consider a sum of independent, identically distributed random variables and the convex barrier cb(n/c), where c is a scale parameter and n is time. It is shown, using large-deviation techniques, that the limit distribution of the first passage time decays exponentially in c. Under a tilt of measure, which changes the drift, four properties are proved: the limit distribution of the overshoot is distributed as an overshoot over a linear barrier; the stopping time is asymptotically normally distributed when it is properly normalized; the overshoot and the asymptotic normal part are asymptotically independent; and the overshoot over a linear barrier is bounded by an exponentially distributed random variable. The determination of the function that multiplies the exponential part is guided by consideration of these properties.

Wang and Pötzelberger (1997) derived an explicit formula for the probability that a Brownian motion crosses a one-sided piecewise linear boundary and used this formula to approximate the boundary crossing probability for general nonlinear boundaries. The present paper gives a sharper asymptotic upper bound of the approximation error for the formula, and generalizes the results to two-sided boundaries. Numerical computations are easily carried out using the Monte Carlo simulation method. A rule is proposed for choosing optimal nodes for the approximating piecewise linear boundaries, so that the corresponding approximation errors of boundary crossing probabilities converge to zero at a rate of O(1/n2).

An unbiased estimator is given for the drift of a Wiener process which is observed up to a stopping time. For first-passage times across a moving boundary the estimator can be calculated by a simple modification of standard computer programs for computing the first-passage density. Examples and interpretations of the estimator are given.

The co-twin control model using paired-comparison analysis provides an extremely powerful and cost-effective experimental design for clinical research. This paper suggests the possibility of using sequential analysis to further increase the efficiency and specificity of cotwin control studies.

A class of probability models for the firing of neurons is introduced and treated analytically. The cell membrane potential is assumed to be a one-dimensional random walk on the continuum; the first passage of the moving boundary triggers a nerve spike, an all-or-none event. The interspike interval distribution of first-passage time is shown to satisfy a Volterra integral equation suitable for numerical evaluation. Explicit solutions as well as their Laplace (Mellin) transforms are obtained for some special cases. The main technique used in this paper is the extension of Wald's fundamental identity of sequential analysis to a wide range of additive stochastic processes with an (eventually) linear boundary function. This identity is also useful in evaluating model parameters in terms of observed firing times, as well as providing a unified exposition of many earlier results.

An identity, of the type of Green's equation, is deduced for the loss function of a stopping process. This yields a set of relations determining the optimal (minimal loss) stopping boundary, which do not require simultaneous determination of the loss function in the stopping region. A no-overshoot approximation is invoked, but a bound on the magnitude of the terms neglected is obtained by appeal to a general version of Chernoff's tangency condition at an optimal boundary.