An examination of the effect of six types of error perturbation on fifteen clustering algorithms

An evaluation of several clustering methods was conducted. Artificial clusters which exhibited the properties of internal cohesion and external isolation were constructed. The true cluster structure was subsequently hidden by six types of error-perturbation. The results indicated that the hierarchical methods were differentially sensitive to the type of error perturbation. In addition, generally poor recovery performance was obtained when random seed points were used to start theK-means algorithms. However, two alternative starting procedures for the nonhierarchical methods produced greatly enhanced cluster recovery and were found to be robust with respect to all of the types of error examined.     

Probability of directional errors with disordinal (qualitative) interaction

In a factorial design with two or more factors, there is nonzero interaction when the differences among the levels of one factor vary with levels of other factors. The interaction is disordinal or qualitative with respect to a specific factor, sayA, if the difference between at least two levels ofA is positive for some and negative for some levels of the other factors. Using standard methods of analysis, there is a potentially large probability of drawing incorrect conclusions about the signs of differences in the presence of disordinal interaction. The maximum probability of such incorrect conclusions, or directional errors, is derived for two-factor designs in which the factor of interest has two levels and the number of levels of the other factor varies.     

Prejudice and peace: Is the Swedish youth neutral in its attitudes?

Two hundred and sixty Swedish students attending grade 9 were given a semantic differential to measure their attitudes towards four countries, Sweden, West Germany, USA, and the Soviet Union. The Soviet Union received significantly more unfavourable ratings on nearly all variables than the other countries, which received mainly favourable or neutral ones. Most interesting, the Soviet Union is rated as "enemy", whilst the other countries are rated as "friends". Implications for peace education are discussed.     

Peer tutoring among elementary students: educational benefits to the tutor

To determine whether tutoring might be academically beneficial to the tutor, this study investigated the acquisition of spelling words by three elementary students in a peer tutoring program. The experimental design allowed a simultaneous comparison of each child's gain in performance on comparable word lists on which the child tutored another child, was tutored by another child, or neither gave nor received tutoring. The children's spelling improved nearly an equivalent amount on those words on which they tutored another child as on the words on which they were tutored; no such change was noted on the words on which they neither gave nor received tutoring. These findings, that peer tutoring is profitable for the tutor as well as the tutee, provide a basis for recommending peer tutoring as one method of individualizing education.     

A multi-element analysis of the effect of teacher aides in an "open"-style classroom

Open classrooms with few rules, individualized instruction, and informal class organization present new problems for the application of behavior principles. The effects of three types of teacher aides on student achievement and on-task behavior were studied. Each was compared with a standard no-aide condition. Subjects were 54 third graders in two "open"-style classrooms. The three types of aide, helping adult, disciplinary adult, and helping fifth-grade aide, were compared in a multi-element design with a no-aide control. The helping-adult aide significantly affected the academic output of the class, when compared with the no-aide condition. All aide conditions produced more academic work and on-task behavior than did the standard no-aide condition.     

Time-series analysis in operant research

A time-series method is presented, nontechnically, for analysis of data generated in individual-subject operant studies, and is recommended as a supplement to visual analysis of behavior change in reversal or multiple-baseline experiments. The method can be used to identify three kinds of statistically significant behavior change: (a) changes in score levels from one experimental phase to another, (b) reliable upward or downward trends in scores, and (c) changes in trends between phases. The detection of, and reliance on, serial dependency (autocorrelation among temporally adjacent scores) in individual-subject behavioral scores is emphasized. Examples of published data from the operant literature are used to illustrate the time-series method.     

TEACHING COIN EQUIVALENCE TO THE MENTALLY RETARDED1

A program was designed to teach coin equivalence to mentally retarded adolescents. Coin equivalence was defined as choosing several different combinations of coins to equal specified target values. A pretest-posttest matched-groups design was employed with an experimental group receiving the monetary training, and a no-training control group. A multiple baseline across coin-counting responses was also incorporated in the experimental group. Training was divided into six stages, each teaching one specific method of combining coins to equal 10 target values from 5¢ through 50¢. A three-component response chain was used, requiring (a) naming, (b) selecting and counting, and (c) depositing target monetary values into a coin machine. Experimental subjects improved significantly in coin equivalence performance and maintained their skill on follow up tests; control subjects did not.     

INCREASING EXTENDED CARE FACILITY RESIDENTS' ATTENDANCE AT RECREATIONAL ACTIVITIES WITH CONVENIENT LOCATIONS AND PERSONAL INVITATIONS1

Residents of extended care facilities generally exhibit a low level of attendance at recreational and therapeutic activities. Spatial arrangement of rooms, prompting, snacks, and small prizes have been suggested as factors that affect attendance. The present study examined the effects of an extensive system of prompts and the location of activity areas on the attendance of residents at a variety of activities. Twenty-six subjects were randomly selected from the ambulatory population of the facility. The first time each subject entered the activity room during the first 6 min of an activity session their name was recorded. Reliability measures were taken at 10 sessions, with a 95% mean agreement between observers. The variables examined were the amount of individualization of subjects (experimental group I: names announced versus experimental group 2: names not announced), room location (central or peripheral), use of names in announcements (activity only versus activity and group I names), and mode of announcement (PA system only versus PA system and in-person). A counter-balanced group design with repeated measures was used, with a randomly determined order of application of experimental treatments. An analysis of variance split plot 2.222 (Kirk, R. E. Experimental Design: Procedures for the Behavioral Science. Belmont, Ca.: Brooks-Cole, 1968.) of the level of subject attendance yielded significant main effects for room location, F(1, 24) = 5.47, p < 0.05, and type of announcement, F(1, 24) = 9.10, p < 0.01, and significant interactions for Individualization × Use of Names in Announcements, F(1, 24) = 5.57, p < 0.05, and Room Location × Mode of Announcement, F(1, 24) = 7.90, p < 0.01. The results indicate that using a centrally located room and announcement of resident names increases attendance at a variety of activities. The increased social and environmental interaction generated by activity attendance has potential therapeutic benefits for the residents involved. Furthermore, the kind of information reported here and by others should be taken into consideration by planners of a variety of group living facilities, ranging from nursing homes to residential treatment cottages.     

Comparing Chinese youth with American youth on adjustment: An illustration of measurement issues in cross-cultural research

In this article, we used results from two studies to show the need to go beyond linguistic equivalence to establish construct validity and measurement invariance in cross-cultural research. Study 1 examined Rosenberg Self-Esteem (RSE; 10 items) data from 156 Mainland Chinese youth (M = 13.8 years, SD = .53) and 213 Chinese-American youth (M = 13.6 years, SD = 2.1) from high socioeconomic status (SES) families. The Chinese translation of the RSE has been widely used. Study 2 included 1060 Mainland Chinese youth (M = 15.6 years, SD = 2.3) and 412 racially diverse American youth (M = 16.0, SD = 2.9) from all SES backgrounds. Data were collected with the third and newest edition of the Behavioural Assessment System for Children-Self Report of Personality (BASC-3-SRP; 189 items). We translated and back-translated the BASC-3-SRP between English and Chinese to establish linguistic equivalence. All participants were females. Study 1 showed that the RSE had acceptable internal consistency but lacked construct validity. Study 2 showed that the original and the translated BASC-3-SRP had good internal consistency and construct validity, but nine of its 16 subscales lacked measurement invariance. These results highlight measurement issues facing international and cross-cultural research.     

Are high levels of religiosity inconsistent with a high valuation of science? Evidence from the United States,China and Iran

We asked whether high levels of religiosity are inconsistent with a high valuation of science. We explored this possibility in three countries that diverge markedly in the relation between the state and religion. Parents in the United States (n = 126), China (n = 234) and Iran (n = 77) completed a survey about their personal and parental stance towards science. The relation between religiosity and the valuation of science varied sharply by country. In the U.S. sample, greater religiosity was associated with a lower valuation of science. A similar but weaker negative relation was found in the Chinese sample. Parents in the Iranian sample, by contrast, valued science highly, despite high levels of religiosity. Given the small size of our United States and Iranian samples, and the non-probabilistic nature of our samples in general, we caution readers not to generalise our findings beyond the current samples. Despite this caveat, these findings qualify the assumption that religiosity is inconsistent with the valuation of science and highlight the role of sociocultural context in shaping adults' perception of the relation between religion and science.