An empirical investigation of the statistical properties of generalized single-case randomization tests

Adapting Edgington's [J. Psychol. 90 (1975) 57] randomly determined intervention start-point model, Levin and Wampold [Sch. Psychol. Quart. 14 (1999) 59] proposed a set of nonparametric randomization tests for analyzing the data from single-case designs. In the present study, the performance of Levin and Wampold's four basic tests (independent start-point general and comparative effectiveness, simultaneous start-point general and comparative effectiveness) was examined with respect to their Type I error rates and statistical power. Of Levin and Wampold's four tests, all except the independent start-point comparative effectiveness test maintained their empirical Type I error rates and had acceptable power at larger sample-size and effect-size combinations. The one-tailed comparative intervention effectiveness test for the independent start-point model was found to be too liberal, in that it did not maintain its Type I error rate. Although a two-tailed application of that test was found to be conservative at longer series lengths, it had acceptable power at larger sample-size and effect-size combinations. The results support the utility of a versatile new class of single-case designs that permit both within- and between-unit statistical assessments of intervention effectiveness.     

Assessing Parenting Behaviors in Euro–Canadian and East Asian Immigrant Mothers: Limitations to Observations of Responsiveness

The use of parenting measures that are developed for use with Western families without testing their validity among families from non-Western cultural backgrounds may not be appropriate. Similar parenting behaviors may affect child outcomes in different ways across different cultures. This study examined the cross-cultural validity of an observational Maternal Responsiveness coding system and of self-reports of lax/inconsistent parenting in Euro–Canadian (n = 23) and East Asian immigrant mothers (n = 23) of 4- to 7-year-old sons. In Euro–Canadian mothers, observed parenting responsiveness was associated with less lax/inconsistent parenting and fewer child behavior problems. In East Asian immigrant mothers, however, observations of greater responsiveness were not related to reports of lax/inconsistent parenting, and were associated with greater child behavior problems. Implications for the use of these parenting measures across culture groups are discussed.     

Parenting Beliefs and Locus of Control Orientation

Parenting beliefs and parents' perceptions of locus of control (LOC) were investigated. Parents (n = 167 dyads) of first-born children, ages 3 months (n = 80) and 3 years (n = 87), representing rural (n = 60) and urban (n = 107) families, completed LOC measure and sorted behavioral statements for actual and ideal parenting beliefs using Q-sort methodology. Factor analysis determined LOC factors for fathers and mothers. Q-sort responses factored into four profiles, each containing four subgroups of parents based on type of sort (actual/ideal) and sex of parent (mother/father). An analysis of variance investigated the relationships between profiles and LOC factors. Mothers who believed in fate stressed educational materials and good nutrition as behaviors of the ideal parent but stressed sharing and educational toys in actual interaction with their children. Mothers who believed they had control over event outcomes emphasized affection and verbal interaction as behaviors of the ideal parent. Fathers who indicated the ideal parent should stress good health habits and teach responsibility believed they had more power over their lives than did fathers who emphasized creativity and verbal interaction. Parents placed daily show of affection for children among the most important behaviors whereas threatening child abandonment was among the least desirable behaviors.     

The Nuts and Bolts of Behavioral Observation of Marital and Family Interaction

Despite considerable discussion in the literature about the advantages of observational research and the relative benefits of different coding systems and strategies, little is written about the actual implementation of this assessment strategy. This paper presents an overall framework as well as the essential components involved in collecting (selection of task, setting, unit of analysis, and coding system) and coding (transcribing, selecting and training coders, transforming data, and analyzing reliability) of observational data. To achieve success with observational methods, we emphasize several issues, including (a) the research question as the motivator for all decisions, (b) the interrelatedness of tasks, and (c) the implications of decisions early in the process for later stages of analysis and interpretation. Investigators are encouraged to communicate the details of their observational and coding procedures so that these methods are readily accessible for purposes of replication and comparison.     

Gross overactivity: A study by direct observation

A group of children who were rated as grossly overactive by a clinician was compared with a matched control group on various measurements of their behavior in a clinical interview situation and in a psychological test situation. An observational schedule was developed to discern those behaviors related to the concept of overactivity. These behaviors were operationally defined to enable reliable replication. The experimental group showed an excess in quantity of mechanically recorded movement as well as an increase in a cluster of behaviors including distractibility and disinhibition. Situational effects on those symptoms were noted. The symptoms were best observed in a semistructured clinical interview situation.This project was carried out while S. L. Luk was a research worker at the Institute of Psychiatry, London, supported by the University of Hong Kong. The authors express sincere thanks to Dr. S. Sandberg for her help in the reliability study, to Dr. J. Bacon-Soong for his statistical advice, and to Miss Ivy Wong for secretarial help.The coding scheme is available from the author.     

Toward an empirically based parameter selection for time-sampling observation systems

The measurement error of time-sampling observation systems, used to estimate the frequencyof behavioral events, was analyzed by means of a five-factor design, computer simulation experiment. The first three factors represented response parameters: the relative frequency and duration of the behavior and the pattern of response distribution. For each combination of frequency, pattern, and duration, five simulated behavior events were generated within a simulated observation period of 900 sec. A total of 21 different time-sampling systems was employed. As a fourth factor three different observe and record lengths were included (6, 12, and 60 sec). In addition, there were seven different ratios of “observe” to “record” interval length (5∶1, 3∶1, 2∶1, 1∶1, 1∶2, 1∶3, and 1∶5) representing the fifth factor. Thus, 21 time-sampling systems scanned a total of 120 different behavior simulations from 24 types of behavior parameter combinations. The data were analyzed by means of a five-factor (2 × 3 × 4 × 3 × 7) analysis of variance with repeated measures on two factors. The study demonstrated that time sampling leads to high average measurement errors, which are determined by complex interrelationships among a variety of variables. Choosing a time-sampling system arbitrarily may lead to highly erroneous data. It was also shown, however, that time-sampling systems have the potential to yield very accurate results. An empirical selection procedure for time-sampling intervals is proposed to minimize measurement error. Exemplary tables are presented from which time-sampling parameters can be chosen given that the rate, duration, and pattern of occurrence of a behavior to be observed are known.     

Seeing vs. believing: Is believing sufficient to activate the processes of response co-representation?

It has been suggested that the observation of another person's action affects the behavior of the observer because the observation of action leads to the excitation of similar response codes in the observer. It is unknown, however, if one must witness the action or if it is sufficient for one to believe that the other agent is responding for response co-representation to occur. To this end, participants in the present study performed a joint spatial-compatibility task with a confederate when: (1) the confederate sat beside the participant; and, (2) the confederate left the room and told the participant that they would continue to perform their component of the task on a networked computer in another room. Even though participants believed that the confederate performed the task in another room, joint spatial-compatibility was only observed when the confederate was present. These results reveal that the actions of another person may only be represented by the observer when the observer is able to witness a portion of the action.     

COMPUTERIZED SYSTEMS FOR COLLECTING REAL-TIME OBSERVATIONAL DATA

Advances in computer technology have led to the development of a number of semiautomated systems for collecting real-time observational data. We conducted a survey of 15 developers of computerized systems and summarized the features of each system. Many of these systems have incorporated laptop or handheld computers as well as bar-code scanners. Most systems used IBM-compatible (DOS or Windows) software, although a few were designed for either the MacOS or some other operating system. The range in prices started from free to more complete systems costing over $1,500. Data analysis programs were included with most programs; however, only about a third of the systems included a program to compute interobserver agreement.