How to Avoid Exploratory Research

Studies in marketing research often start with data rather than with a theory. This exploratory or inductive approach is at odds with the more preferred scientific method where the theory precedes the data in any single research study. (See, for example, the discussion by Francis, 1957) Because exploratory research is common, however, one might argue that it is of some value. A number of researchers have claimed that the exploratory approach leads to new and useful theories. But there is also the danger that the research will produce false leads or useless theories. An attempt is made in this paper to illustrate the dangers inherent in the exploratory approach. The question of whether the potential benefits are large enough to outweigh the dangers is left to the reader.

Structured Analogies for Forecasting

When people forecast, they often use analogies but in an unstructured manner. We propose a structured judgmental procedure that involves asking experts to list as many analogies as they can, rate how similar the analogies are to the target situation, and match the outcomes of the analogies with possible outcomes of the target. An administrator would then derive a forecast from the experts information. We compared structured analogies with unaided judgments for predicting the decisions made in eight conflict situations. These were difficult forecasting problems; the 32% accuracy of the unaided experts was only slightly better than chance. In contrast, 46% of structured analogies forecasts were accurate. Among experts who were independently able to think of two or more analogies and who had direct experience with their closest analogy, 60% of forecasts were accurate. Collaboration did not improve accuracy.accuracy, analogies, collaboration, conflict, expert, forecasting, judgment.

Are Student Ratings of Instruction Useful?

Despite the lead article^Rs title ^SValidity Concerns and Usefulness of Student Ratings of Instruction^T (Greenwald 1997) in the American Psychologist^R^Rs special section on teacher ratings, the papers did not provide direct evidence on ^Susefulness.^T There is no evidence that the use of teacher ratings improves learning in the long run. The papers do not show that the effects would improve the allocation of effort between teaching and research, or that the quality of the educational experience will be better, or that students and faculty will be happier. Given the evidence to date, the case for student ratings is weak. I raise some questions about usefulness, with a particular emphasis on the ratings^R effects on learning.learning, universities

Derivation of Theory by Means of Factor Analysis or Tom Swift and His Electric Factor Analysis Machine

Problems in the use of factor analysis for deriving theory are illustrated by means of an example in which the underlying factors are known. The actual underlying model is simple and it provides a perfect explanation of the data. While the factor analysis 'explains' a large proportion of the total variance, it fails to identify the known factors in the model, The illustration is used to emphasize that factor analysis, by itself, may be misleading as far as the development of theory is concerned. The use of a comprehensive, and explicit à priori analysis is proposed so that there will be independent criteria for the evaluation of the factor analytic results.factor analysis

The Graffiti Solution

Graffiti is regarded by many as a blight on our cities because it contributes to visual pollution. City governments spend vast sums in an effort to clean the ubiquitous graffiti from urban walls. I suggest that the ^Scleansing strategy^T is an expensive, ineffective way of dealing with the problem; well-known management techniques can solve the problem more efficiently.graffiti problem, graffiti solution

Improving Learning at Universities: Who is Responsible?

Recently, I published a letter in the Wall Street Journal (Armstrong 2004a) with the basic message that business school education has been losing effectiveness. Most important, students are not learning to do things, such as making an effective oral presentation, writing a persuasive management report, listening to others, conducting a meeting, or using statistical procedures to analyze data. This problem is not confined to business schools; it is plaguing the educational system on almost every level. My letter drew responses from alumni, faculty, recruiters, consultants, and students. Nearly all of them agreed with my assessment, claiming that the problem is rampant but ignored. As I will show below, however, evidence-based suggestions can resolve the problem.learning, universities

Global Warming: Forecasts by Scientists versus Scientific Forecasts

In 2007, the Intergovernmental Panel on Climate Change’s Working Group One, a panel of experts established by the World Meteorological Organization and the United Nations Environment Programme, issued its Fourth Assessment Report. The Report included predictions of dramatic increases in average world temperatures over the next 92 years and serious harm resulting from the predicted temperature increases. Using forecasting principles as our guide we asked: Are these forecasts a good basis for developing public policy? Our answer is “no”. To provide forecasts of climate change that are useful for policy-making, one would need to forecast (1) global temperature, (2) the effects of any temperature changes, and (3) the effects of feasible alternative policies. Proper forecasts of all three are necessary for rational policy making. The IPCC WG1 Report was regarded as providing the most credible long-term forecasts of global average temperatures by 31 of the 51 scientists and others involved in forecasting climate change who responded to our survey. We found no references in the 1056-page Report to the primary sources of information on forecasting methods despite the fact these are conveniently available in books, articles, and websites. We audited the forecasting processes described in Chapter 8 of the IPCC’s WG1 Report to assess the extent to which they complied with forecasting principles. We found enough information to make judgments on 89 out of a total of 140 forecasting principles. The forecasting procedures that were described violated 72 principles. Many of the violations were, by themselves, critical. The forecasts in the Report were not the outcome of scientific procedures. In effect, they were the opinions of scientists transformed by mathematics and obscured by complex writing. Research on forecasting has shown that experts’ predictions are not useful in situations involving uncertainly and complexity. We have been unable to identify any scientific forecasts of global warming. Claims that the Earth will get warmer have no more credence than saying that it will get colder

Dispersive properties of quasi-phase-matched optical parametric amplifiers

The dispersive properties of non-degenerate optical parametric amplification in quasi-phase-matched (QPM) nonlinear quadratic crystals with an arbitrary grating profile are theoretically investigated in the no-pump-depletion limit. The spectral group delay curve of the amplifier is shown to be univocally determined by its spectral power gain curve through a Hilbert transform. Such a constraint has important implications on the propagation of spectrally-narrow optical pulses through the amplifier. In particular, it is shown that anomalous transit times, corresponding to superluminal or even negative group velocities, are possible near local minima of the spectral gain curve. A possible experimental observation of such effects using a QPM Lithium-Niobate crystal is suggested.Comment: submitted for publicatio

Higher twists in the pion structure function

We calculate the QCD moments of the pion structure function using Drell-Yan data on the quark distributions in the pion and a phenomenological model for the resonance region. The extracted higher twist corrections are found to be larger than those for the nucleon, contributing around 50% of the lowest moment at Q^2=1 GeV^2.Comment: 8 pages, 3 figures, to appear in Phys. Rev.

Effects of C, Cu and Be substitutions in superconducting MgB2

Density functional calculations are used to investigate the effects of partial substitutional alloying of the B site in MgB2 with C and Be alone and combined with alloying of the Mg site with Cu. The effect of such substitutions on the electronic structure, electron phonon coupling and superconductivity are discussed. We find that Be substitution for B is unfavorable for superconductivity as it leads to a softer lattice and weaker electron-phonon couplings. Replacement of Mg by Cu leads to an increase in the stiffness and doping level at the same time, while the carrier concentration can be controlled by partial replacement of B by C. We estimate that with full replacement of Mg by Cu and fractional substitution of B by C, Tc values of 50K may be attainable.Comment: 5 pages, 4 figure