Kevin Bird

• PhD
• Lecturer at UNSW Sydney

Researchers who conduct randomized experiments are typically interested in estimating the magnitude of the effects of experimental interventions on various outcome measures. These estimates are often expressed as confidence intervals (CIs) that specify a range of plausible values of the effect size in measurement units specific to the particular ou...

Multivariate experiments are often analyzed by multistage multiple-comparison procedures (MCPs) that prohibit univariate testing on individual dependent variables if an overall multivariate analysis of variance (MANOVA) test fails to reject the relevant overall null hypothesis. Although the sole function of the MANOVA test in such analyses is to co...

Any set of confidence interval inferences on J − 1 linearly independent contrasts on J means, such as the two comparisons μ1 − μ2 and μ2 − μ3 on 3 means, provides a basis for the deduction of interval inferences on all other contrasts, such as the redundant comparison μ1 − μ3. Deduced inference does not inflate the experimentwise error rate beyond...

Two experiments examined the acquisition and loss of “craving” or liking for a food (unsalted peanuts). In Experiment 1, subjects were allocated to three conditions. In each of these, they ingested a few peanuts on three separate occasions and were then asked to indicate the strength of their cravings for that food. The conditions differed in terms...

The present study investigated differential relationships, nonlinear relationships, and multiplicative relationships among the subdimensions of extraversion (agency and affiliation) and job performance (getting ahead and getting along) for a sample of 179 managers. We found that: (i) agency was positively related to getting ahead performance, where...

The current study provides an exposition of artificial neural network (ANN) methodology in the context of research on personality and work performance. We demonstrate some of the benefits and limitations of this methodology relative to multiple regression (MR) for conducting exploratory research. Using three data sets that each contained personalit...

Objective: This study used a prospective design and the technique of structural modelling to examine the complex interrelations between psychological factors, immune status and complications after major surgery. Methods: Twenty-nine women scheduled for elective cholecystectomy were studied prospectively. Information regarding medical history, healt...

Hazardous alcohol use is a leading cause of death among adolescents and young adults world-wide, yet few effective prevention interventions exist. This study was the first to examine a computerized harm minimization intervention to reduce alcohol misuse and related harms in adolescents. Cluster randomized controlled trial of a six-session curriculu...

The authors provide generalizations of R. J. Boik's (1993) studentized maximum root (SMR) procedure that allow for simultaneous inference on families of product contrasts including simple effect contrasts and differences among simple effect contrasts in coherent analyses of data from 2-factor fixed-effects designs. Unlike the F-based simultaneous t...

Previous research has generallyfailed to find a relation between the waystudents approach the task of studying andtheir exam grades. The present studyinvestigated why it is that a deep approach tostudying, which has been shown to result in ahigher quality of learning, does notconsistently result in higher exam grades. Theparticipants in the study w...

Although confidence interval procedures for analysis of variance (ANOVA) have been available for some time, they are not well known and are often difficult to implement with statistical packages. This article discusses procedures for constructing individual and simultaneous confidence intervals on contrasts on parameters of a number of fixed-effect...

Path analysis was used to examine the antecedents of posttraumatic stress (PTS) symptoms in Tamil asylum-seekers, refugees, and immigrants in Australia. The Harvard Trauma Questionnaire and a postmigration living difficulties questionnaire were completed by 62 asylum-seekers, 30 refugees, and 104 immigrants who responded to a mail-out. Demographic...

Patients with chronic fatigue syndrome (CFS) report neuro-psychological symptoms as a characteristic feature. We sought to assess cognitive performance in patients with CFS, and compare cognitive performance and subjective workload experience of these patients with that of two disease comparison groups (non-melancholic depression and acute infectio...

Simple, reliable measures of the quality of the environment in which a child was reared that can be used in clinical research and practice are lacking. The reliability and validity of a global scale to retrospectively appraise the quality of that environment were examined. Fifty-three clinicians from 4 centers in Australia and 1 in Hong Kong, Peopl...

To ascertain whether nocturnal enuresis in adolescents is associated with depression, hyperactivity, oppositionality, conduct and peer problems. This was investigated cross-sectionally in adolescents aged 12-16 years from a community sample (n = 528) and a clinically referred cohort (n = 2325) using parents' reports. Referred adolescents were 7 tim...

SYNOPSIS To determine whether patients diagnosed as having chronic fatigue syndrome (CFS) constitute a clinically homogeneous class, multivariate statistical analyses were used to derive symptom patterns and potential patient subclasses in 565 patients. The notion that patients currently diagnosed as having CFS constitute a single homogeneous class...

This study involved 137 participants who were assessed on 12 relevant predictor variables and then randomly assigned to social support or self-control treatment. Outcome across treatments was predicted by cotinine levels, treatment history, previous abstinence, happiness, self-efficacy, and perceived social support for quitting. Social support trea...

The relationship between and the inter-rater reliability of the Composite International Diagnostic Interview (CIDI) and the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) for anxiety and depressive disorders were explored. The CIDI and the SCAN were administered by trained interviewers in counterbalanced order. A subsample of interview...

To assess whether perceived parental care and protection varied according to age and gender of the child and whether they were associated with psychiatric diagnoses, these constructs were measured with the Parental Bonding Instrument in a cohort of non-referred adolescents (n = 762), in a clinically referred cohort (n = 1299), and in a group of ado...

A method is outlined for the analysis of the shape of an individual profile of scores on a standardized test battery such as the WAIS-R. The method makes use of a simultaneous test procedure allowing for an overall test of profile flatness, together with follow-up tests on all contrasts of interest, including any that may be suggested by an examina...

Reports of suicidal behaviour from four countries using the same measures were higher for girls than for boys, and higher in self-reports than in parent reports for both referred and normal adolescents. In a sample of 480 referred adolescents, patterns of 'low' and 'high' suicidal scores were different when age, sex and diagnosis were considered. T...

A dose-response study of the effect of orally administered delta 9-tetrahydrocannabinol (THC) on human mood and skills performance was conducted. Using five dose levels of THC (0, 5, 10, 15, 20 mg) with 16 volunteers per dosage group, mood and performance measures were recorded at five testing occasions, one before and four after drug administratio...

A dose-response study of the effect of orally administered Δ9-tetrahydrocannabinol (THC) on human mood and skills performance was conducted. Using five dose levels of THC (0, 5, 10, 15, 20 mg) with 16 volunteers per dosage group, mood and performance measures were recorded at five testing occasions, one before and four after drug administration. Th...

Methods are outlined for performing simultaneous multiple comparisons between groups when the dependent variable is one in which subjects are assigned to one of two or more categories. These methods provide tests which are analogous to Scheffe- and Bonferroni-adjusted tests of contrasts in the analysis of variance. Examples are provided of each of...

Statistical power is neglected in much psychiatric research, with the consequence that many studies do not provide a reasonable chance of detecting differences between groups if they exist in the population. This paper attempts to improve current practice by providing an introduction to the essential quantities required for performing a power analy...

The multiple comparison problem arises in any research design in which the scores of more than two groups are compared on a single dependent variable. The analysis of variance provides a way of testing the null hypothesis that all population means are equal with a type 1 error rate of alpha. When the joint null hypothesis is accepted, the outcome o...

This paper deals with the problem of multiple inference in psychiatric research, an issue which arises whenever a researcher has to make more than one statistical inference in a single research study. It frequently arises in psychiatric research because of multivariate study designs, with subjects being measured on more than one dependent variable...

The involvement of central endogenous opioids in swim-induced antinociception in mice is well documented. The response is attenuated by central or systemic naloxone, displays two-way cross tolerance with morphine and is correlated with apparent occupation of central opiate receptors by endogenous ligands. Swim-induced antinociception was utilised a...

Methodology developed in our laboratories for testing the interactive effects of ethanol and drugs on human psychomotor performance is discussed. An attempt has been made to relate the findings of our studies to the results of real-life impairment, particularly in traffic crashes. Proposals for more comprehensive testing of drug--ethanol interactio...

Suggests that problems associated with the use of a preliminary MANOVA test in conjunction with univariate follow-up tests can be avoided if follow-up tests are carried out with a simultaneous test procedure (STP) derived from the MANOVA test statistic used for the overall test. It is argued that the choice of a MANOVA test statistic for such analy...

In a study designed to investigate the effect of naloxone on ethanol-induced performance deficits in man, ethanol (0.75 g/kg) and naloxone (0.4 mg) or saline were administered to 39 volunteers in a double-blind fashion. Psychomotor performance was assessed on a battery of tests (standing steadiness, pursuit rotor, simple and complex reaction times,...

Mice which had been made to swim for 3 minutes showed a tail flick latency which was significantly longer than that of unswum controls. The [3H] leu-enkephalin [LE] binding to brain homogenates from swum mice was significantly reduced when compared with that form unswum controls. Scatchard analysis revealed that the reduction in binding occurred at...

The cannabinoids (THC, 215 μ/kg; CBD, 320 μg/kg; CBN, 320 μg/kg) and ethanol (0.54 g/kg) were administered orally to human volunteers alone and in all possible combinations and performance decrements were assessed on a battery of tests (standing steadiness, simple and complex reaction times, pursuit rotor and Vienna Determination Apparatus) over a...

Fifteen volunteers received cannabidiol (CBD) (320 microgram/kg) or placebo (both orally, T0), and 60 min later they consumed an ethanolic beverage (0.54 g/kg) or placebo. The effects were measured at T1 (100 min after CBD ingestion), T2 (160 min) and T3 (220 min) using cognitive, perceptual and motor function tests. Factorial analysis indicated th...

Twenty five volunteers received (-) Δ 9-tetrahydrocannabinol (THC) (320 μg/kg) or placebo (both orally, T0), and, 60 min later, they consumed an ethanolic beverage (0.54 g/kg) or placebo. The effects of this medication were measured at T1 (100 min after THC ingestion), T2 (160 min), T3 (220 min) and T4 (280 min) using a battery of cognitive, percep...

Twenty five volunteers received (-) trans-delta9-tetrahydrocannabinol (THC) (320 microgram/kg) or placebo (both orally, T0), and, 60 min later, they consumed an ethanolic beverage (0.54 g/kg) or placebo. The effects of this medication were measured at T1 (100 min after THC ingestion), T2 (160 min), T3 (220 min) and T4 (280 min) using a battery of c...

Simultaneous test procedures associated with multivariate analysis of variance provide very little power for tests of contrasts written on individual variates or on planned linear combinations of variates. Generalizations of the Scheffe, Tukey, and Bonferroni-t techniques are presented, each of which controls the experimentwise error rate for a par...