Methods in Psychological Research

Psychologists collect empirical data with various methods for different reasons. These diverse methods have their strengths as well as weaknesses. Nonetheless, it is possible to rank them in terms of different critieria. For example, the experimental method is used to obtain the least ambiguous conclusion. Hence, it is the best suited to corroborate conceptual, explanatory hypotheses. The interview method, on the other hand, gives the research participants a kind of emphatic experience that may be important to them. It is for the reason the best method to use in a clinical setting. All non-experimental methods owe their origin to the interview method. Quasi-experiments are suited for answering practical questions when ecological validity is importa

Experimentation in Psychology--Rationale, Concepts and Issues

An experiment is made up of two or more data-collection conditons that are identical in all aspects, but one. It owes its design to an inductive principle and its hypothesis to deductive logic. It is the most suited for corroborating explanatory theries , ascertaining functional relationship, or assessing the substantive effectiveness of a manipulation. Also discussed are (a) the three meanings of 'control,' (b) the issue of ecological validity, (c) the distinction between theory-corroboration and agricultural-model experiments, and (d) the distinction among the hypotheses at four levels of abstraction that are implicit in an experiment

Some meta-theoretical issues relating to statistical inference

This paper is a reply to some comments made by Green (2002) on Chow’s (2002) critique of Wilkinson and Task Force's (1999) report on statistical inference. Issues raised are (a) the inappropriateness of accepting methodological prescription on authority, (ii) the vacuity of non-falsifiable theories, (iii) the need to distinguish between experiment and meta﷓experiment, and (iv) the probability foundation of the null﷓hypothesis significance﷓test procedure (NHSTP). This reply is intended to foster a better understanding of research methods in general, and of the role of NHSTP in empirical research in particular

Auotmatic detection, consistent mapping, and training

Results from two experiments showed that a flat display﷓size function was found under the consistent mapping (CM) condition despite the facts that there was no extensive CM training and that the stimulus﷓response (S﷓R) consistency was only an intrasession manipulation. A confounding factor might be responsible for the fact that the consistent and the varied S﷓R mapping conditions gave rise to different display﷓size functions in Schneider and Shiffrin's (1977) study. Their claim that automatic detection and controlled search are qualitatively different is also discussed

Issues in Statistical Inference

The APA Task Force’s treatment of research methods is critically examined. The present defense of the experiment rests on showing that (a) the control group cannot be replaced by the contrast group, (b) experimental psychologists have valid reasons to use non-randomly selected subjects, (c) there is no evidential support for the experimenter expectancy effect, (d) the Task Force had misrepresented the role of inductive and deductive logic, and (e) the validity of experimental data does not require appealing to the effect size or statistical power

Cognitive Science and Psychology

The protocol algorithm abstracted from a human cognizer's own narrative in the course of doing a cognitive task is an explanation of the corresponding mental activity in Pylyshyn's (1984) virtual machine model of mind. Strong equivalence between an analytic algorithm and the protocol algorithm is an index of validity of the explanatory model. Cognitive psychologists may not find the index strong equivalence useful as a means to ensure that a theory is not circular because (a) research data are also used as foundation data, (b) there is no justification for the relationship between a to﷓be﷓validated theory and its criterion of validity, and (c) foundation data, validation criterion and to﷓be﷓validated theory are not independent in cognitive science. There is also the difficulty with not knowing what psychological primitives are

Iconic memory of icon?

The objectives of the present commentary are to show that (1) one important theoretical property of iconic memory is inconsistent with a retinotopic icon, (2) data difficult for the notion of an icon do not necessarily challenge the notion of an iconic store, (3) the iconic store, as a theoretical mechanism, is an ecologically valid one, and (4) the rationale of experimentation is such that the experimental task need not mimic the phenomenon being studied

Application of Subset Simulation to Seismic Risk Analysis

This paper presents the application of a new reliability method called Subset Simulation to seismic risk analysis of a structure, where the exceedance of some performance quantity, such as the peak interstory drift, above a specified threshold level is considered for the case of uncertain seismic excitation. This involves analyzing the well-known but difficult first-passage failure problem. Failure analysis is also carried out using results from Subset Simulation which yields information about the probable scenarios that may occur in case of failure. The results show that for given magnitude and epicentral distance (which are related to the ‘intensity’ of shaking), the probable mode of failure is due to a ‘resonance effect.’ On the other hand, when the magnitude and epicentral distance are considered to be uncertain, the probable failure mode correspondsto the occurrence of ‘large-magnitude, small epicentral distance’ earthquakes

Ridge preservation comparing a flap vs. a flapless technique using a demineralized bone matrix allograft plus mineralized particulate allograft and covered with a calcium sulfate barrier.

Aims . The primary aim of this study is to compare the clinical and histologic results of a flap vs. a flapless technique of ridge preservation after 4 months of healing. Both groups received an intrasocket graft of demineralized bone matrix mixed with mineralized particulate allograft that was covered with a calcium sulfate barrier. Methods . Twelve test patients received ridge preservation using the flapless technique while 12 positive control patients were treated with a flap technique. All sockets were grafted with a mixture of demineralized bone matrix and a mineralized particulate allograft. Following tooth extraction horizontal ridge dimensions were measured with a digital caliper and vertical ridge dimensions were measured from a stent. Each site was re-entered for implant placement at about 4 months. Prior to implant placement a 2 X 6 mm trephine core was obtained and preserved in formalin for histologic analysis. Results . The horizontal ridge width of the flapless group at the crest decreased from 8.3 ± 1.3 mm to 7.0 ± 1.9 mm for a mean loss of 1.3 ± 0.9 mm (p \u3c 0.05) while the flap group decreased from 8.5 ± 1.5 mm to 7.5 ± 1.5 mm for a mean loss of 1.0 ± 1.1 mm (p \u3c; 0.05). There were no statistically significance differences between the two groups (p \u3e 0.05). The mean mid-buccal vertical change for the flap group was a loss of 0.9 ± 1.3 mm (p \u3c 0.05) vs. a loss of 0.5 ± 0.9 mm (p \u3c 0.05) for the flap group. There were no statistically significant differences between groups for vertical change (p \u3e 0.05). Histologic analysis revealed 44 ± 10% vital bone for the flapless group and 35 ± 15% for the flap group. Non-vital bone was 17 ±13% for the flapless group and 19 ± 12% for the flap group. Conclusions . Crestal ridge width following treatment with a flapless ridge preservation procedure using a demineralized bone matrix plug allograft and a calcium sulfate barrier was not significantly different than a flap ridge preservation technique using the same materials. There was a trend toward less loss of ridge height when the flapless procedure was used, although the difference was not statistically significant (p \u3e 0.05)

Screening for Breast Cancer: U.S. Preventive Services Task Force Recommendation Statement

DESCRIPTION: Update of the 2009 U.S. Preventive Services Task Force (USPSTF) recommendation on screening for breast cancer. METHODS: The USPSTF reviewed the evidence on the following: effectiveness of breast cancer screening in reducing breast cancer-specific and all-cause mortality, as well as the incidence of advanced breast cancer and treatment-related morbidity; harms of breast cancer screening; test performance characteristics of digital breast tomosynthesis as a primary screening strategy; and adjunctive screening in women with increased breast density. In addition, the USPSTF reviewed comparative decision models on optimal starting and stopping ages and intervals for screening mammography; how breast density, breast cancer risk, and comorbidity level affect the balance of benefit and harms of screening mammography; and the number of radiation-induced breast cancer cases and deaths associated with different screening mammography strategies over the course of a woman's lifetime. POPULATION: This recommendation applies to asymptomatic women aged 40 years or older who do not have preexisting breast cancer or a previously diagnosed high-risk breast lesion and who are not at high risk for breast cancer because of a known underlying genetic mutation (such as a BRCA1 or BRCA2 gene mutation or other familial breast cancer syndrome) or a history of chest radiation at a young age. RECOMMENDATIONS: The USPSTF recommends biennial screening mammography for women aged 50 to 74 years. (B recommendation) The decision to start screening mammography in women prior to age 50 years should be an individual one. Women who place a higher value on the potential benefit than the potential harms may choose to begin biennial screening between the ages of 40 and 49 years. (C recommendation) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening mammography in women aged 75 years or older. (I statement) The USPSTF concludes that the current evidence is insufficient to assess the benefits and harms of digital breast tomosynthesis (DBT) as a primary screening method for breast cancer. (I statement) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of adjunctive screening for breast cancer using breast ultrasonography, magnetic resonance imaging (MRI), DBT, or other methods in women identified to have dense breasts on an otherwise negative screening mammogram. (I statement)