Sep 30th, 2009
by Rense Nieuwenhuis.
With the Triumph of Numbers, I read and wrote about the power of using numbers, and how the observation of empirical regularities led to the basic knowledge on how to use such numbers. Already in the triumph of numbers, it was indicated how valuable (numerical) data were regarded to be, for instance by the recollection how the first censuses were regarded as state secrets, because the information could be used to make assertions about the military strength of (rival) nations.
Unfortunately, I.B. Cohen’s Triumph of Numbers ended quite abruptly with a description of Florence Nightingale. It felt unfinished. But the use of numbers has evolved since, and quite substantially so.
How much our use of numerical data has evolved, and to what extent is has invaded our daily lives (without many of us knowing it!), is convincingly described by Ian Ayers, in his magnificent book ‘Super Crunchers’ (2007).
Companies know more and more (and more!) about you: you buy products online, you speak with the customer relations department (with a person behind a computer), you gain discounts with customer cards, and of course you are careful to make sure you receive you frequent flyer miles. Right? If not, you may have bought it all using a credit card, the transactions of which are stored anyway. Continue reading →
Posted in: Book, Reading List, Science.
Tagged: experiment · Ian Ayres · Reading List · regression · Science · super crunchers
Sep 23rd, 2009
by Rense Nieuwenhuis.
Recently, I was contacted with an question about R code. A befriended researcher was working with nested data, which was unbalanced. He was working with data in a ‘long’ format: all observations nested within the same group had the same identification number. But, the number of observations in each of the groups differed (hence: unbalanced data).
He asked me for a piece of code that creates a subset of the data that is balanced, i.e. all observations that are nested within equally sized groups. Or, as an alternative, all observations nested within groups with at least a minimum number of observations.
I solved it the quick and dirty way, and the solution involves creating additional variables, a new data.frame, and merging. It sure can be done much prettier, but it works.
So, I share it below:
Continue reading →
Posted in: R-Project, R-Sessions.
Tagged: balanced data · merge · R · R-Sessions · subset · unbalanced data
Sep 16th, 2009
by Rense Nieuwenhuis.
How does one teach statistics? Is it more important to start with mathematical thoroughness, or to help students to gain a conceptual understanding first? Few give a comprehensive introduction to statistics for those without the otherwise indispensable mathematical background. Manfred te Grotenhuis and Theo van der Weegen recently published an introductory book on statistics, explaining statistical concepts using words and graphs, rather than formulas.
Less than a year ago, I wrote these exact words. I then discussed the publication of a Dutch book on statistics, to which I provided minor assistance. Now, I repeat these words to introduce the Enligsh translation of this conceptual introduction to statistics, called Statistical Tools. Again, I contributed to this publication, this time by providing a first, rough, translation from Dutch to English. Let me repeat below what I wrote before on this blog, for of course this still holds relevance for the translation to English:
With the focus on practical application rather than statistical theory, the first chapter starts explaining the goal of inferential statistics, meanwhile introducing the concepts of measurement and variables. Considerable attention is paid to the importance of high quality data to perform your analyses on. The second chapter Continue reading →
Posted in: Reading List.
Tagged: Book · statistical tools · Statistics · te grotenhuis · van der weegen
Sep 8th, 2009
by Rense Nieuwenhuis.
My new job involves working with numbers. A lot. So, I started reading about using numbers, and I very much enjoyed ‘The Triumph of Numbers’ by I.B. Cohen (2005). This book gives an historical account not only of how numbers were used in different times, but also of ‘how counting shaped modern life’.
The books starts out by illustrating the power of numbers. Just by using very simple calculations, Cohen quickly arrives at the conclusion that the building of the ancient pyramids involved placing one giant block of stone in the structure, every two minutes. Since the weight of such stones is enormous, this required quite advanced techniques to achieve. Knowing the vast size of such an operation, this helps us to gain an understanding in how the Egyptians may have done it, and the level of technology available to them.
For long, people have been fascinated by numbers. Cohen’s description of the history of using numbers therefore starts with numerology. The reader is treated with lovely exercises is numerology: it is quite amazing how we can prove about anything, simply by reordering numbers that somehow correspond to letters. If only there was an empirical basis for such magic.
Off to more serious applications of numbers (by today’s standards), Cohen locates the proper start of using numbers in Hutcheson’s Moral Arithmetic. Hutcheson used formulae (and which are based on numbers) to make his claims about morality. Here, numbers were only used to illustrate a claim, but not much later people started to relate such numbers to observable phenomena. An example of this Benjamin Franklin, who used his mathematical genius to find arguments based on numbers for his political claims regarding the safety of inoculation against smallpox. He used numbers to show it was safe to have your children inoculated.
Continue reading →
Posted in: Book, Reading List, Science, Statistics.
Tagged: Cohen · Nightingale · numbers · nursing · Quetelet · sociology · Statistics
Sep 3rd, 2009
by Rense Nieuwenhuis.
Last Tuesday, I posted the preface of my Master’s Thesis on my blog. In an earlier draft, I wrote some thoughts about what I learned during my education in Sociology. In the end, I decided to delete that passage, but I saved it for publication on my blog.
So, below some thougths on what I learned about sociology:
[My] thesis completes my research master Social and Cultural Sciences, which I started upon my obtaining a Bachelor’s degree in sociology. In many ways, this thesis forms an accumulation of the lessons I learned. Three of those important lessons regard a trinity of a perspective on science, of how to theorize, and of method.
During my education, I developed a perspective on science, influenced by both Karl Popper and Thomas Kuhn. Within the rules set by a specific paradigm, I attempt to elaborate upon the core idea(s) of such paradigm by asking new questions that build on existing ones, by using theories to formulate prelimirary answers to these questions, and finally by testing these new answers against empirical evidence with as much rigor as possible.
Regarding the formulation of explanations derived from theory, I was inspired by the principle of methodological individualism. Based on this principle, I learned the importance of analyzing social phenomena that are observable at the macro level by formulating explanations at the level of the individual.
Finally, regarding the method of research, I was taught both survey methodology and a variety of statistical tools that together can provide the rigor required to test the preliminary answers that were derived from theory.
Posted in: Science.
Tagged: preface · sociology · thesis
Sep 1st, 2009
by Rense Nieuwenhuis.
Just very recently I finished writing my Master’s Thesis, it was graded last week, and today I’m starting my new job as a PhD Candidate. I will be working at the department of Social Risk and Safety Studies, at the University of Twente. I will be working on a project regarding cross-country differences in the socio-economic outcomes of fertility related decisions. I’m sure to be writing more about this project in the coming four years.
Regarding my Master’s thesis, it studies polarization in North American’s abortion attitudes. I was able to locate a very nice lacuna in the literature, and built upon existing literature to solve this lacuna. But, without further ado, I will let the preface speak for itself:
Attitudes on the permissibility of induced abortion vary widely in the United States of America. How people think about abortion has often been the topic of scholarly studies, which highlighted aspects ranging from the level of the streets with protests either ‘pro-life’ or ‘pro-choice’, to the level of legislation and Supreme Court rulings, to the public opinion on abortion. The question whether public opinion on abortion has become more polarized received substantial attention of social scientists, as well. This study adds to this body of literature on polarization in the North Americans’ public opinion on induced abortion. It contributes a new explanatory framework on polarization of public opinion which allows much of the existing literature to be brought together, a suggestion for a statistical approach for analyzing hypotheses derived from this model, and new hypotheses derived from this model.
Continue reading →
Posted in: My Thesis.
Tagged: abortion · attitudes · new job · polarization · thesis
Jul 30th, 2009
by Rense Nieuwenhuis.
Last weekend, the magazine of NRC Handelsblad (a major Dutch newspaper), featured an interview with Rebecca Gomperts, the founder of Women on Waves. Women on Waves is “a Dutch non-profit organization concerned with women’s human rights. Its mission is to prevent unwanted pregnancy and unsafe abortions throughout the world.” One of their activities that received most attention of public media, is sailing towards countries that prohibit induced abortion, and then to sail to international waters with women seeking an abortion. On international waters abortion pills can be provided, for on international water the ship falls under Dutch law.
What struck me in the interview, is the enormous amount of difficulties Rebecca Gomperts and Women on Waves have been confronted with. Whereas she had high hopes, ten years ago, for a whole fleet of ‘women on waves’ providing information and aid to women who required it, she recently has had to cancel some of their activities. This is the direct result of changes in Dutch abortion policy.
Partly, she is confronted with unjust allegations. For instance, she discusses the common misrepresentation of Women on Waves, especially reagrding what happens on their boat. The only types of abortion (if it can even be called that way) that are carried out there, are performed using abortion pills, and only in the first 16 days after a woman was expected to start menstruating. Moreover, their emphasis seems to be on providing information, rather than the actual abortion practice.
According to Gompert, the Dutch climate towards induced abortion is changing. Besides recent changes in the Dutch abortion policy, she also discusses how organisations against abortion receive more government funding than organisations in favour of the possibility for abortion. She concludes with being concerned that this financial inequality between organisations may topple public opinion against women’s opportunity to choose.
Posted in: Politics, Remotely Related.
Tagged: abortion · fertility · Rebecca Gomperts · Women on Waves
Jul 29th, 2009
by Rense Nieuwenhuis.
Although the Netherlands are known for their liberal stance on induced abortion, currently the issue is debated again. Two only slightly related subjects now gain considerably attention in popular media and public opinion.
The first is a slight change in policy regarding the use of the ‘abortion pill’ in very early pregnancies (before 16 days after a women was expected to start menstruating). The government decided that regulation regarding this procedure now is part of the abortion legislation (which is wasn’t). Although the government states that this does not change much for abortion practice, opponents argue that this results in a more restrictive abortion legislation.
Secondly, health inspection ordered the prosecution of Women on Waves, a Dutch organisation that uses boats to provide abortions and information to women in countries where abortion is prohibited. By sailing to international waters, their actions are regulated by Dutch legislation, providing a legal basis. Apparently, they violated the law by using the wrong type of boat.
Interestingly, a major Dutch newspaper featured an interview with Rebecca Gomperts, founder of Women on Waves, just this weekend. I’ve already rounded up some thoughts on this interview with the founder of Women on Waves, Rebecca Gomperts, which I will publish tomorrow. So, if you’re interested in this subject, do come back then!
Posted in: Politics, Remotely Related.
Tagged: abortion · fertility · Rebecca Gomperts · Women on Waves
Jul 27th, 2009
by Rense Nieuwenhuis.
New technology has that unique property of creating fascinating moral debates, which is especially so when it relates to new technology regarding life, death, or in this case: fertility. For a few years, technology has been available for the cryo-preservation of oocytes or ovarian tissue, which is used to help save the fertility of women who run the risk of losing it, for instance due to chemotherapy. Now, the question is raised whether such techniques should be made available to healthy women as well.
Continue reading →
Posted in: Blogging on Peer Review Research, Health, Remotely Related.
Tagged: fertility · Health Policy · IVF · Medical Ethics · sociology
Jul 16th, 2009
by Rense Nieuwenhuis.
With the introduction of our new package for influential data influence.ME, I’m currently writing a manual for the package. This manual will address topics for both the experienced, and the inexperienced users.
I will also present much of the content of this manual on my blog. Of course, feel free to comment on it, and readers are encouraged to discuss the content of the manual here. All information will be accessible from the influence.ME website as well. Note that updates to the manual will be made available on that website”, instead of updating this blog post. So, please refer to the influence.ME website for the most up-to-date information.
This is the first section on influence.ME, which deals with a very simply analysis of students nested within 23 schools. Only the effect of a single variable measured at the school level is estimated.
Continue reading →
Posted in: Influence.ME.
Tagged: example · Influence.ME · influential data · lme4 · mixed effects · multilevel
Influence.ME: an R package providing tools for detecting influential data in mixed models.