Election polls: description vs. prediction

My papers To Explain or To Predict and Predictive Analytics in Information Systems Research contrast the process and uses of predictive modeling and causal-explanatory modeling. I briefly mentioned there a third type of modeling: descriptive. However, I haven’t expanded on how descriptive modeling differs from the other two types (causal explanation and prediction). While descriptive and predictive modeling both share the reliance on correlations, whereas explanatory modeling relies on causality, the former two are in fact different. Descriptive modeling aims to give a parsimonious statistical representation of a distribution or relationship, whereas predictive modeling aims at generating values for new/future observations. … Continue reading Election polls: description vs. prediction

Flipping and virtualizing learning

Adopting new technology for teaching has been one of my passions, and luckily my students have been understanding even during glitches or choices that turn out to be ineffective (such as the mobile/Internet voting technology that I wrote about last year). My goal has been to use technology to make my courses more interactive: I use clickers for in-class polling (to start discussions and assess understanding, not for grading!); last year, after realizing that my students were constantly on Facebook, I finally opened a Facebook account and ran a closed FB group for out-of-class discussions; In my online courses on statistics.com … Continue reading Flipping and virtualizing learning

Launched new book website for Practical Forecasting book

Last week I launched a new website for my textbook Practical Time Series Forecasting. The website offers resources such as the datasets used in the book, a block with news that pushes posts to the book Facebook page, information about the book and author, for instructors an online form for requesting an evaluation copy and another for requesting access to solutions, etc. I am already anticipating my colleagues’ question “what platform did you use?”. Well, I did not hire a web designer, nor did I spend three months putting the website together using HTML. Instead, I used Google Sites. This … Continue reading Launched new book website for Practical Forecasting book

New Google Consumer Surveys: revolutionizing academic data collection?

Surveys are a key data collection tool in several academic research areas. As opposed to experiments or field studies that yield observational data, surveys can give access to attitudes, reaching “inside the head” of people rather than observing their behavior. Technological advances in survey tool development now offer “poor academics” sufficiently powerful online survey tools, such as surveymonkey.com and Google forms. Yet, obtaining access to a large pool of potential respondents from a particular population remains a challenge. Another challenge is getting fast responses — how do you reach people quickly and get many of them to respond quickly? We may … Continue reading New Google Consumer Surveys: revolutionizing academic data collection?

Early detection of what?

The interest in using pre-diagnostic data for the early detection of disease outbreaks, has evolved in interesting ways in the last 10 years. In the early 2000s, I was involved in an effort to explore the potential of non-traditional data sources, such as over-the-counter pharmacy sales and web searches on medical websites, which might give earlier signs of a disease outbreak than confirmed diagnostic data (lab tests, doctor diagnoses, etc.). The pre-diagnostic data sources that we looked at were not only expected to have an earlier footprint of the outbreak compared to traditional diagnostic data, but they were also collected … Continue reading Early detection of what?

Google Spreadsheets for teaching probability?

In business schools it is common to teach statistics courses using Microsoft Excel, due to its wide accessibility and the familiarity of business students with the software. There is a large debate regarding this practice, but at this point the reality is clear: the figure that I am familiar with is about 50% of basic stat courses in b-schools use Excel and 50% use statistical software such as Minitab or JMP. Another trend is moving from offline software to “cloud computing” — Software such as www.statcrunch.com offer basic stat functions in an online, collaborative, social-networky style. Following the popularity of … Continue reading Google Spreadsheets for teaching probability?