Higher Degree Research

Five tips from a statistician to a starting HDR student

Congratulations on starting your research degree at ANU! Whether you are on campus or studying remotely, you are joining a large and diverse community of researchers who are all striving to push back the boundaries of knowledge in their field. Thousands of students have graduated from the ANU Honours, Masters and PhD program who have been supported by many more thousand family members, supervisors, other academic and professional staff. Many of them will be more than willing to provide you with tips and advice on how to survive and even thrive over the duration of your course.

The SCU is no different, and over time we have brought together a few tips from our perspective as statistical consultants on how to view the statistical aspects of your research

  1. Seeking statistical advice does not diminish your contribution to the research.

In a statistical consultation, you seek the help of a statistician to select and use the best methods for obtaining and analysing data for some data-related objective. Usually the objective is to answer a research question. The subject area could be almost anything, such as biology, astronomy, archaeology, political science, linguistics or medicine, to name a few. The question is still yours, as is the interpretation of the results.

2. The most effective way to work with a statistical consultant is to include them from the very beginning of the project.

An important advantage of consulting a statistician before a study begins is that they can verify that the planned procedures and size of the study will be adequate to address its goals. They can give advice on blinding/masking and randomization, the number and combination of experimental interventions, the timing of measurements or visits, and other important design issues, such as whether it would be better to collect information on a larger sample or on the same sample more times. A statistician can also suggest ways to maximize the efficient use of the available resources. The statistician can also contribute relevant expertise in decisions about data management from the earliest stages. Decisions about how to code measures, and what to computerize, directly affect the ease, even the feasibility, of subsequent analyses.

3. A statistical consultant can provide advice at every step of the research process.

A statistical consultant can help to select and implement data analysis methods that are appropriate and effective for the types of data produced by your study. In order to do this, the statistician needs to have a complete, detailed description of the study design and conduct, as well as a clear exposition of the questions to be addressed. A statistician should know (or may be able to develop) statistically valid ways to obtain answers to your questions. Also, they will examine your data for threats to validity, ranging from missing data to questionable outliers to confounders.

Once the data are analysed, the results must be interpreted and conveyed to an audience, such as a conference audience, a research journal, or an examiner. A statistician can be valuable at this stage, too, by checking that your conclusions fit the results, by suggesting the best ways to describe and display the data. A statistician who is first consulted at this stage may actually need to re-analyse the data using methods they consider more appropriate than those already tried.

4. Some studies cannot be rescued, even with the input of a statistician.

If the study procedures did not provide data that could answer the research question, the statistician will not be able to remedy this with statistical methods; however, they may be able to point out what information can be extracted from the data.

5. Statisticians love playing in other people’s backyards.

This tip is based on a quotation from the mathematician / statistician / computer scientist John Tukey. In addition to talking about the project, most statisticians appreciate receiving written summary material. You might include background information about the problem, including a description of the project, equipment, or procedures to be evaluated; diagrams or flow-charts that illustrate important ideas and processes; or information about any existing database to be used.

It is not always possible or necessary to have complete information on all of these, and frequently the need for information becomes apparent in the discussion. Nevertheless, starting with a couple of pages of background information gets the process off to a good start, saves time later and enables the consultant to give you a more realistic estimate of the time to complete the project.

This post was based on the material in the American Statistical Association’s publication “When you consult a statistician … what to expect.”

Associate Professor Alice Richardson is Director of the Statistical Consulting Unit (SCU) at the Australian National University. Her research interests are in linear models and robust statistics; statistical properties of data mining methods; and innovation in statistics education. In her role at the SCU she applies statistical methods to large and small data sets, especially for research questions in population health and the biomedical sciences.

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