Misconceptions of probability: An experiment with a small-group,activity-based,model building approach to introductory probability at the college level

Summary The day-by-day observations made by the experimenter during one of the activity-based classes indicate that college students can learn to discover some elementary probability models and formulas for themselves while working on probability experiments in small groups. Furthermore, the effects of sample size upon measures of central tendency and variability can be learned by students working on activities such as those developed for the experimental course in this study. Making guesses for the probability of events and checking guesses with a hand-held calculator seems to help college students to be more cautious about probability estimates, and helps to make them aware about some of their own misconceptions about probability. Small-group problem solving, keeping a log of all class work and activities, and investigating the misuses of statistics all appeared to have a positive effect upon college students' attitudes towards mathematics, as indicated in the questionnaires filled out by the subjects in the experimental sections.The present results of this study support the hypotheses of Kahneman and Tversky [10, 12] which claimed that combinatorially naive college students rely upon availability and representativeness to estimate the likelihood of events. Kahneman and Tversky were skeptical about the possibility of helping students to overcome their reliance upon availability and representativeness. The results on the posttest in this study suggest that the manner in which college students learn probability makes a difference in their ability to overcome misconceptions that arise from availability and representativeness. Mere exposure to probability concepts is not sufficient to overcome certain misconceptions of probability. Fischbein [9] notes that the synthesis between the necessary and the possible-which is the basis of probabilistic thinking-does not in fact take place spontaneously .... He claims that science education emphasizes only the deterministic aspect, and neglects the study of uncertainty. Thus peoples' intuition of probabilistic thinking is distorted by science education's emphasis on the necessary, and neglect of the possible. This experiment suggests that the course methodology and the teaching model used in an elementary probability course can help develop peoples' intuition for probabilistic thinking. A course in which students carry out experiments, work through activities to build their own probability models, and discover counting principles for themselves can help students to overcome their misconceptions about probability, and can help restore the synthesis between the necessary and the possible which is essential to probabilistic thinking.     

Four-year follow-up study of language impaired children

Children identified as normal or as specifically language impaired (SLI) were given speech, language, and intelligence testing on a longitudinal basis. Fourteen normal and 29 SLI children between the ages of 4 1/2 and 8 years were tested at Time 1. They were retested three to four years later when they were 8 to 12 years old. The results indicated that both the normal and the SLI children continued to develop skills in receptive and expressive language and speech articulation across the 3- to 4-year period intervening between evaluations. Overall, however, the SLI children appeared to develop language skills at a slower than normal rate and 80% of them remained language impaired at Time 2. In addition, the majority of the SLI children manifested reading impairment at Time 2, while none of the normal children did so. The implications for the educational management of SLI children are discussed. Research supported by the March of Dimes, Grant #12-84. Presented at the 32nd Annual Conference of The Orton Dyslexia Society, Baltimore, Maryland, November 1982.     

Suicide intervention: Training,roles, and knowledge of school psychologists

Practitioner‐members of the National Association of School Psychologists (N = 162) completed questionnaires regarding their suicide prevention and postvention roles, training, preparedness, and knowledge. Most were crisis team members, yet less than one‐half reported graduate training in suicide risk assessment and less than one‐fourth in postvention. Compared to nondoctoral‐level practitioners, doctoral‐trained practitioners felt better prepared to handle suicidal students. Most respondents had participated in a suicide risk assessment in the past 2 years, with few using standardized measures. Performance was moderately strong on questions about knowledge of risk factors, warning signs, and appropriate steps to respond to a suicidal student, but respondents showed less familiarity with postvention recommendations intended to discourage contagion. Training suggestions were identified. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 157–170, 2007.     

Time demands in online instruction1

This article reports findings from a Mellon Foundation research project at Syracuse University with regard to the time demands placed on teachers and learners in online courses. This exploratory research was primarily a study of cases involving three online courses and one face‐to‐face course. The focus of the study was the effects of different forms of communication and collaboration on time invested by teachers and learners. The online courses made use of e‐mail, threaded discussion forums, and online chat sessions; the face‐to‐face course used e‐mail in addition to a course Web site and lectures. Learning outcomes and retention in the three online courses were similar to outcomes and retention in comparable face‐to‐face courses at this institution. Students invested slightly more time in online courses whereas faculty, all of whom were experienced online teachers, invested considerably more time in their online courses. An analysis of interviews with online teachers at other institutions confirms the finding that experienced online teachers invest significantly more time in online teaching than their counterparts in face‐to‐face settings.     

Density functional theory study of the adsorption of elemental mercury on a 1T-MoS<Subscript>2</Subscript> monolayer

Elemental mercury has become a global concern because of its significant impact on human health and the ecosystem. A lot of effort has been put towards the removal of elemental mercury from the 2H-MoS₂ (prismatic structure of MoS₂). However, the mechanism of 1T-MoS₂ (polytype structure of MoS₂) in Hg⁰ capture remains unexplored. In this study, density functional theory (DFT) was adopted to investigate the adsorption mechanism of Hg on a 1T-MoS₂ monolayer. The different possible adsorption positions on the 1T-MoS₂ were examined. For different adsorption configurations, the changes in electronic property were also studied to understand the adsorption process. The results elucidated that chemisorption dominates the adsorption between Hg⁰ atoms and the 1T-MoS₂. It was found that the T_Mo (on top of the Mo atom) position is the strongest adsorption configuration among all the possible adsorption positions. The adsorption of Hg⁰ atoms on the 1T-MoS₂ monolayer is influenced by adjacent S and Mo atoms. The adsorbate Hg0 atom is found being oxidized on the T_Mo position of the 1T-MoS₂ with an adsorption energy of ?1.091 eV. From the partial density of states (PDOS) analysis of the atoms, the strong interaction between Hg⁰ and the 1T-MoS₂ surface is caused by the significant overlap among the d orbitals of the mercury atom and the s orbital of the S atom and p and d orbitals of the Mo atom.     

Spatial task solving on tablets: analysing mental and physical rotation processes of 12–13-year olds

Educational technology research and development - Spatial skill assessment and training are promising fields of application for tablets, as touch-based interaction can prime and support mental...     

The determinants of progress to the doctoral degree

The time doctoral students expect to take to complete their degree is investigated in a model which stresses the effects of economic factors. The model also accounts for the interdependency among such variables as employment hours, study hours, household income, and part-time study. We find that field of study, amount of borrowing, household income, and study hours have direct effects on expected time to degree. Indirect effects also occur from employment hours and the amount of fellowship, scholarship, or grant aid. When the sample is separated into foreign and U.S. students, we find that U.S. students underestimate their time to degree. Also, household incomes are higher for U.S. students and increase the time to degree, while the opposite is true for foreign students. Teaching assistantships increase the time to degree for foreign students while research assistantships reduce it.