Recent advances in machining of Austempered Ductile Iron to avoid machining induced microstructural phase transformation reaction

Austempered Ductile Iron (ADI) is a type of nodular, ductile cast iron subjected to heat treatments-austenitising and austempering. Whilst machining is conducted prior to heat treatment and offers no significant difficulty, machining post heat treatment is demanding and often avoided. Phase transformation of retained austenite to martensite leading to poor machinability characteristics is a common problem experienced during machining. Study of phase transformations is an investigative study on the factors-plastic strain (εp) and thermal energy (Q) which effect phase transformations during machining. The experimental design consists of face milling grade 1200 at variable Depth of Cut (DoC) range from 1 to 4 mm, coolant on/off, at constant speed, 1992 rpm and feed rate, 0.1 mm/tooth. Plastic strain (εp) and martensite content (M) at fracture point for each grade was evaluated by tensile testing. The effect of thermal energy (Q) on phase transformations was also verified through temperature measurements at DoC 3 and 1 mm using thermocouples embedded into the workpiece. Finally, the amount of plastic strain (εp) and thermal energy (Q) responsible for a given martensite increase (M) during milling was related and calculated using a mathematical function, M=f (εp, Q). The future work of the thesis involves an in-depth study on the new link discovered through this research: mathematical model relating the role of plastic strain and thermal energy in martensite formation.

Evaluation of the usefulness of 'Marvin'; a computerized assessment tool for investigative interviewers of children

This study examined the usefulness of a computerized developmental assessment tool, designed to provide investigative interviewers with knowledge about children's understanding of spatial, temporal, numerical, and color terms that may be relevant to the forensic setting. Specifically, the effect of the computer program (compared to a standard verbal and no assessment) was examined on 4- to 5-year-old children's recall of an independent event and their enjoyment of the interview process. In addition, children's performance on the computerized and verbal developmental assessment was compared with their performance when recalling the independent event. Overall, the children rated the assessment conducted on computer more favorably than the verbal assessment. Further, the verbal assessment elicited responses that were more consistent with their responses about the event than the computerized assessment. However, there was no difference in the accuracy and detail of children's responses about the independent event, irrespective of whether the children received the computerized or verbal assessment, or no assessment. Directions for future research are discussed.

Investigative interviewers' perceptions of their difficulty in adhering to open-ended questions with child witnesses

Best practice guidelines for conducting investigative interviews of children emphasise the importance of obtaining free narrative accounts with the use of open-ended questions. However, research indicates that most investigative interviewers underutilise open-ended questions, even following intensive training in their use. The aim of the current study was to explore investigative interviewers' perceptions of their difficulty in asking open-ended questions. During a training course on how to use open-ended questions, eight child abuse investigators were individually interviewed about why they had asked specific questions in a 10-minute mock interview conducted immediately earlier with a school child. Overall, three reasons were identified. These related to: 1. the specificity of the information required from children; 2. the unfamiliar nature of the open-ended discourse style; and 3. the complex distinction between open-ended versus specific questions. Each of these themes is discussed, along with the implications for trainers and researchers in child investigative interviewing.

Investigative interviewers' perceptions of the value of different training Tasks on their adherence to open-ended questions with children

Prior research has highlighted the considerable difficulties investigative interviewers have in adhering to open-ended questions in child abuse interviews. Although improvements in interviewing can be achieved by providing training that incorporates multiple practice opportunities and feedback, currently little is known about the way in which these elements are best administered. The current study extends debate and research on this issue by examining the perceptions of 15 trainee interviewers (police as well as social workers) regarding the relative value of various practical training exercises experienced in a recent training program. The findings indicated that although practice in interviewing was deemed essential, not all tasks were perceived to be equally beneficial. The two most favoured exercises were (a) simulated interviews involving trained actors playing the role of the child, and (b) self-evaluation of a transcribed interview using an objective coding protocol. A summary of the participants' perceptions is provided along with a discussion of the implications for trainers and researchers.

An examination of the types of leading questions used by investigative interviewers of children

Purpose – The purpose of this paper is to examine the nature of leading questions used by a representative sample of investigative interviewers of children. In particular, it examined whether these interviewers use the type of questions that are known to elicit reports of false activities or events among child samples.
Design/methodology/approach – A total of 82 police officers who were authorized to conduct interviews with alleged child abuse victims conducted individual mock interviews with children aged 5-7 years. The focus of the interviews was an event that was staged in the children's school a week earlier. Prior to the interview, each officer was provided with accurate and inaccurate information about the event, including details about an activity that did not occur. The officers' task was to elicit as detailed and accurate account of the event as possible using the techniques they would “normally” use in the field.
Findings – Although the officers refrained from using coercive interview techniques, two problematic types of questions were relatively common. These include: questions that presumed that an activity/detail occurred that had not been previously mentioned by the child; and questions that included highly specific details about an activity. Both of these techniques had featured in prior laboratory research on children's false event narratives.
Research limitations/implications – These results support the need for better training techniques for assisting officers to avoid the use of leading questions.
Originality/value – While it is well established that investigative interviewers do sometimes use leading questions when interviewing children, this is the first study to specify the incidence of various types of leading questions.of leading questions.

An examination of the limitations in investigative interviewer's use of open-ended questions

Best-practice guidelines in the area of investigative interviewing of children specify the importance of using open-ended questions. However, use of open-ended questions per se does not maximise interview outcome; open-ended questions can vary markedly in quality. The aim of this study was to identify the nature of investigative interviewers' limitations when using open-ended questions, and to compare how representative these limitations are in three distinct interview paradigms. These interview paradigms include: (a) interviews in which trained actors played the role of a 5-6-year-old child; (b) interviews where 5-6-year-old children recalled an innocuous event that was staged in their school; and (c) actual field interviews where child witnesses aged 5 to 7 years recalled an abusive event. Overall, several common problems that would restrict children's opportunity to provide elaborate and accurate narrative accounts of events were identified and described. Our identification of these problems (using a dichotomous rating scale) was found to be consistent with an independent expert, and their presence was not limited to those interviewers who used a low frequency of open-ended questions. The implications of the findings for researchers and trainers in the area of investigative interviewing of children are discussed.

An evaluation of a self-intiated practice exercise for investigative interviewers of children

The current study extends debate and research on the important role of practice in promoting and sustaining complex skills in investigative interviewing. Specifically, we explored the use of self-initiated practice as one avenue for facilitating ongoing development of professionals who interview children about abuse. A group of 40 investigative interviewers were required to organise and administer their own practice opportunities and to document these sessions in a diary. The professionals were aware of the important role of practice and what constitutes best-practice interview guidelines; however no instruction was given about the desired format, structure and timing of the practice sessions. A combination of quantitative and qualitative analyses revealed poor adherence to self-initiated practice, and the practice (among those who adhered to this model) had negligible impact on performance. Overall, these findings highlight the need for careful monitoring and evaluation of all interviewer practice tasks.

Evaluation of the questions used to elicit evidence about abuse from child witnesses : Australian study

This study provides one of the first objective evaluations of the performance of a group of Australian police officers when conducting interviews about child abuse. The interviews included 136 videotaped child witness statements, conducted between 2001 and 2007 by police officers from two jurisdictions of Australia. The results indicated many positive aspects of the interviewers' performance, including the use of ground rules at the outset of the interview, commencement of the free-narrative account by seeking the children's understanding of the purpose of the interview, and avoidance of suggestive questions. But the interviewers tended to raise issues of contention when the child did not provide an initial disclosure, and the proportion of open-ended questions was low relative to specific cued-recall and closed questions. Further many closed questions raised specific details not yet mentioned by the child. These behaviours were exhibited irrespective of the recency of interview or time since training. The implications of these findings are discussed.

Investigative interviewing of children with intellectual disabilities

This research was designed to examine two broad issues in relation to the investigative interviewing of children (aged 9 to 13 years) with mild and moderate intellectual disabilities. First, how do children with intellectual disabilities perform (relative to children matched for chronological and mental age) when recalling an event in response to various questions? Second, what question types and interview strategies do police officers and caregivers use to elicit accurate and detailed accounts about an event from children with intellectual disabilities? The rationale for exploring each of these issues was to determine possible ways of improving the elicitation of evidence from children with intellectual disabilities. While children with intellectual disabilities constitute a high proportion of all child victims of abuse (Conway, 1994; Goldman, 1994; Morse, et ah, 1970), they rarely provide formal reports of abuse and of those incidents that are reported, few cases progress to court (Henry & Gudjonsson, 1999). Study 1 used a standard interview protocol containing a variety of questions and an interview structure commonly used in investigative interviews. Specifically, the memory and suggestibility of eighty children with either a mild and moderate intellectual disability (M age = 10.85 years) was examined when recalling an innocuous event that was staged at their school. The children's performance was compared with that of two control groups; a group of mainstream children matched for mental age and a group of mainstream children matched for chronological age. Overall, this study showed that children with both mild and moderate intellectual disabilities can provide accurate and highly specific event-related information hi response to questions recommended in best-practice guidelines. However, their recall was less complete and less clear in response to free-narrative prompts and less accurate in response to specific questions when compared to both mainstream age-matched groups. Study 2 provided an in-depth analysis of the types of questions and strategies used by twenty-eight police officers and caregivers when interviewing children with either mild or moderate intellectual disabilities (M age = 11.13 years) about a repeated event that was staged at their school. The results revealed that while the approach used by the police officers was generally consistent with best-practice recommendations (i.e., their interviews contained few leading, coercive or negative strategies), there were many ways in which their approach could be improved. This study also showed that the caregivers used a high proportion of direct and negative strategies to elicit information from their children. Even when caregivers used open-ended questions, their children provided less event-related information than they did to police interviewers. The results of both studies were discussed in relation to current 'best-practice' guidelines for interviewing children and recommendations were offered for improving the quality of field interviews with children who have intellectual disabilities.

Examination of the stability and consistency of investigative interviewer performance across similar mock interview contexts

Purpose. Three studies examined the degree to which investigative interviewers’ adherence to best-practice guidelines is consistent across similar mock interviews.
Method. In each study, two interviews were administered within a period of several hours. Further, group and individual stability of interviewer performance was analysed, and performance was measured by calculating the proportion of open-ended and leading questions as well as the presence of predetermined problem behaviours. The studies varied depending on the type of interview paradigm employed. Interviewer performance in Study 1was measured in a group context where participants rotated between the role of interviewer, child respondent, and observer. In Study 2, an adult played the role of a child recalling abuse but this occurred in isolation (participants did not observe others or play the child). Study 3 was similar to Study 2 except that in each interview an unfamiliar child aged 5–7 years recalled an innocuous event.
Results. Interviewer performance was relatively stable across tasks, although the strength of the relationship between measures varied across analyses. Improvement in open-ended question usage occurred in Study 1 but not Studies 2 and 3. Irrespective of the assessment context, the dichotomous rating scale yielded greater consistency than when questions were tallied. Further, group stability overestimated individual stability. The practical implications of these findings for trainers and researchers are discussed.

The association between investigative interviewers' knowledge of question type and adherence to best-practice interviewing

It is well established that not all investigative interviewers adhere to ‘best-practice’ interview guidelines (i.e., the use of open-ended questions) when interviewing child witnesses about abuse. However, little research has examined the sub skills associated with open question usage. In this article, we examined the association between investigative interviewers' ability to identify various types of questions and adherence to open-ended questions in a standardized mock interview. Study 1, incorporating 27 trainee police interviewers, revealed positive associations between open-ended question usage and two tasks; a recognition task where trainees used a structured protocol to guide their response and a recall task where they generated examples of open-ended questions from memory. In Study 2, incorporating a more heterogeneous sample of 40 professionals and a different training format and range of tests, positive relationships between interviewers' identification of questions and adherence to best-practice interviewing was consistently revealed. A measure of interviewer knowledge about what constitutes best-practice investigative (as opposed to knowledge of question types) showed no association with interviewer performance. The implications of these findings for interviewer training programs are discussed.

What themes trigger investigative interviewers to ask specific questions when interviewing children?

Recent research has established that investigative interviewers have difficulty adhering to openended questions and instead ask specific questions when interviewing children about abuse. The current study aims to examine the themes in abuse-related interviews that trigger investigators to ask specific questions. Twenty police officers who were authorised to conduct investigative interviews with children completed a mock interview with an expert in child abuse interviewing who had been trained to play the role of an abused child. During the interview, the officers were stopped by a researcher and asked to reflect on why they had asked specific questions. Overall, the results revealed five areas where the officers deviated from open-ended questions. These related to: (1) the identity of the alleged offender; (2) the meaning of terms used by the child to describe genitals; (3) whether or not penetration occurred; (4) the offender's intent and motives; and (5) the timing of the abuse and where it occurred. Each of these themes is discussed, along with the implications for trainers and researchers in child abuse interviewing.

Workplace stressors for investigative interviewers of child-abuse victims

Purpose - This study aimed to identify the nature and prevalence of workplace stressors faced by interviewers of child sexual assault victims.

Design/methodology/approach - Sixty-eight professionals (police and child protection workers) were invited to anonymously post their perceptions of workplace stressors on an internet forum as part of an investigative interviewing online training course. Specifically, participants were asked to reflect on salient sources of stress encountered in their role of interviewing sexually abused children.

Findings - Three key stressors were identified across the study’s professional groups: (1) inadequate recognition of specialised skills; (2) high workload demands; and (3) interagency tensions. Consistent with previous research, exposure to child abuse reports was not raised as a stressor.

Research limitations/implications - Our study generated suggestions for modifying management practices; however, future research should identify and trial strategies for improving workplace climate in child abuse investigation.

Practical implications - As the stressors isolated by participants related to workplace climate rather than exposure to victims’ accounts of child abuse, minimising negative consequences of work stressors requires changes to workplace culture and practice. Workplace climates need to be modified so that the demands are offset by resources.

Originality/value - Because of its online, anonymous nature, this was the first study to offer participants the opportunity to honestly disclose primary sources of stress in child abuse investigation. The research also makes a much-needed contribution to an area of police practice that is vital yet often overlooked.

Errors in the identification of question types in investigative interviews of children

This study examined the incidence and nature of the errors made by trainee coders during their coding of question types in interviews in which children disclosed abuse. Three groups of trainees (online, postgraduate and police) studied the coding manual before practising their question coding. After this practice, participants were given two-page field transcripts to code in which children disclosed abuse. Their coding was assessed for accuracy; any errors were analysed thematically. The overall error rate was low, and police participants made the fewest errors. Analysis of the errors revealed four common misunderstandings: (1) the use of a ‘wh’ question always denotes a specific cued-recall question; (2) ‘Tell me’ always constitutes an open-ended question; (3) open-ended questions cannot include specific detail; and (4) specific questions cannot elicit elaborate responses. An analysis of coding accuracy in the one group who were able to practise question coding over time revealed that practice was essential for trainees to maintain their accuracy. Those who did not practise decreased in coding accuracy. This research shows that trainees need more than a coding manual; they must demonstrate their understanding of question codes through practice training tasks. Misunderstandings about questions need to be elicited and corrected so that accurate codes are used in future tasks.

Improving child investigative interviewer performance through computer-based learning activities

The current study adopted a pre- versus post-training design and a standardised measure of performance to evaluate the effectiveness of a series of online computerbased learning activities designed to encourage open-ended question usage among investigative interviewers of children. Participants included 61 social workers, police and psychologists. The learning activities, organised into 12 modules of approximately 3 hours duration each, focused purely on the skill of eliciting a disclosure of sexual abuse and a narrative account of the offence from a young child. Results revealed a significant improvement in interview performance from pre-training to immediate post-training. For the 25 participants who also completed a follow-up assessment three to six months after completing the learning activities, performance was found to be maintained. The implications of these findings and directions for future research are discussed.