Archives for : March 2018

Conference season kick-off  1

 March 29, 2018  
The tallest building was our conference venue – not bad!

 

 

 

 

 

 

 

 

 

 

 

After a quiet wintertime, the conference season has officially started! As a researcher, you experience certain peak-times during the year, which are often related to… conferences. For example, in August we usually have to submit papers for international conferences. In January, we submit papers for national conferences held in summer. And just before the international conferences which usually start in April, we have to finish our analyses, write papers and prepare for meetings with our international colleagues who are sometimes our advisors, co-authors or make up our reference-list.

As a lot of ICLON researchers will attend AERA (American Educational Research Association) in New York this year, I will write this blog about a different conference which not so many ICLONners attended: the NARST (National Association for Research in Science Teaching) in Atlanta, US.

Luckily, I was not totally on my own in Atlanta. Because I also have supervisors and colleagues from Delft, we traveled together. With two of my colleagues, we boarded a direct flight to Atlanta on March 8th, 2018. The all-American man sitting two rows behind us was a little disappointed when we told him we were attending a conference (he might have expected something more exciting), but nonetheless told us to “not let them cowboys snatch you up!”.

 

Our view from Amsterdam to Atlanta.

 

 

 

 

 

 

 

 

 

 

 

On our first day in Atlanta, the conference had not started and we did some sightseeing. Although Atlanta is known for many things (Martin Luther King, World of Coca Cola, Say Yes to the Dress, and according to Google the nicest tree-house AirBnB), we decided to go to the Georgia Aquarium, which has an almost 24-million-liter water tank hosting four giant whale sharks, several manta rays and loads of fish. Upon return to our hotel, we ironed our clothes and refined our presentations, as the next day, the conference would start.

 

Breakfast at the Waffle House – not so healthy but a must-do for the all-American experience!

 

 

 

 

 

 

 

 

 

 

Whale sharks in the Georgia Aquarium.

 

 

 

 

 

 

 

 

 

 

 

I had a great time presenting my research in a symposium hosted by my promotor, Jan van Driel, and the three other presenters which I had already met once at the PCK summit. During the conference, there were a lot of presentations by PCK researchers, and it was very informative. Gradually, I met a lot of people who I formerly just knew from their names, which often appeared on my reference list (for example Tamara Moore, Selcen Guzey, Barbara Crawford, Kennedy Chan). If anyone wants more information on the presentations given at NARST, I’d be happy to inform you!

 

I held my presentation during the last session of the first day. Photo by Dury Bayram.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I study the integration of engineering design activities and research activities (or scientific inquiry, as most American researchers call it), and this was the first conference where there were so many presentations and sessions on this topic. I feel that this topic might be more prominently addressed in American education as the National Research Council and the Next Generation Science Standards have also placed emphasis on the combination of research and design in STEM. The Dutch subject O&O (Onderzoeken & Ontwerpen, the Dutch abbreviation for Research & Design) which forms the context of the study I presented, also gained a lot of interest among international researchers.

 

View over Atlanta.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

After four days of conference, and 6 days in Atlanta, I flew home feeling very content with such a productive conference. At this moment, I am still having email conversations with people I met there. It was my first time in the US and my first time at the NARST, and I can really recommend this conference if you’re working on science education as well!

 

Anyone fancy a souvenir…?

 

 

 PHD 

Do you use Cronbach’s alpha to check internal consistency? Don’t! Use Summability.  0

 March 26, 2018  

Do you sum questions of your exams to get final scores of students? Do you use a questionnaire with likert-scales? Do you analyze these questionnaires by taking the means of these questionnaire-items? Do you use the mean of questions in evaluation-forms? Do you average response times to items in experimental settings?

 

If you have answered yes to any of these questions, you may (or may not but should) have wondered whether the items in your questionnaire, exam, test, or experiment are (sort of) measuring the same thing, the construct you had intended to be measured. If so, it is more than likely that you have calculated Cronbach’s alpha and (if the value was over .7) happily reported that indeed, the items were internally consistent. If so, you have calculated and reported the wrong measure and you are not alone. Despite the fact that methodologists have shown numerous time that Cronbach’s alpha is not suitable for measuring internal consistency (see Sijtsma, 2009, for instance), in handbooks Cronbach’s alpha can still be found as the prime choice measure to be calculated. Because the intention of questionnaire and test constructers is to summarize the test by its overall sum score, Jelle Goeman (and myself) advocate summability, which is defined as the proportion of total “test” (questionnaire-subset, exam, evaluation) variation that is explained by the sum score.

 

Our paper recently came out in the journal Educational Measurement: Issues and Practice, in which we show summability to be a stable measure across a number of variables (including test or questionnaire length). From the few examples that have been calculated until now, and from insight in the mathematic formula, we can assume that a summability of .5 can be considered “high”. As yet, however, more experience has to be gained on summabilities of tests in various fields before definite recommendations can be given.

 

Therefore, I end this blog with a “Call for Calculations”: please go to (https://sites.google.com/view/summability) and calculate summability yourself, for an existing test, exam, questionnaire, or experiment. You can download the R-code from the website, or use the link to the shiny-app. All you need is a table with items as columns and participants as rows, filled with participants’ scores on the items, supposedly measuring your (one) construct. The table can be in plain text-format or it can be an SPSS-file. Report your scores through the form available on the website. In this way, we will be able to gain a fast accumulation of knowledge of what constitutes “high,” “moderate,” and “low” summabilities. Thank you!

 teacher research