Many of the earliest posts on this blog dealt with the nuts and bolts of research methodology, and with questionnaire research in particular. This page brings them together in one place. I have written it mainly with postgraduate students and teacher-researchers in language education in mind, although much of the advice travels to other fields.
The posts are grouped by the stage of research you are likely to be at, rather than by date (dates refer to the year when a post was created, although many of them have been updated since then). Each entry comes with a short note on when it might be useful. If you are a teacher interested in research more broadly (reading it, using it, or exploring your own classroom), the companion page, Resources for Research Literacy, may be a better place to start.
Start here
If you only have time for three posts, these are the ones I would suggest:
How to use Likert scales effectively
Many questionnaires use Likert items & scales to elicit information about language teaching and learning. In this post, I discuss how to use these instruments effectively, by looking into the difference between items and scales, and explaining how to analyse the data that they produce.
Can You Take the Mean of Likert Scale Data? Ordinal vs Interval Explained
A lot of research, in applied linguistics and language education at least, relies on a recurring statistical mistake: averaging ordinal data, such as that produced by Likert scales. Here’s why you shouldn’t do it, and what you should do instead.
Likert scales: Four things you may not know
If you use quantitative methods in your research project, you may want to read this first.
Contents of this page
1. Designing a questionnaire
- Writing effective questionnaire items in language education research (Part 1) (2014). Useful when you are drafting items and want to avoid three of the most common problems.
- Writing effective questionnaire items in language education research (Part 2) (2014). Useful when you need to formulate and sequence the items in your questionnaire.
- Dealing with demographic data in language education research (2014). Useful when you are designing the background section of a survey.
- How to use Likert scales effectively (2014). Useful when you are building Likert items and scales and want to understand the difference between them.
- Designing questionnaires in language education research: Layout (2014). Useful when your items are ready and you need to think about the practical side of presenting them.
2. Analysing Likert-scale data
- Likert scales: Four things you may not know (2013). Useful when you are about to use Likert scales and want to check your assumptions.
- Can You Take the Mean of Likert Scale Data? Ordinal vs Interval Explained (2013). Useful when you are tempted to average Likert responses.
- How to Interpret Likert Scales: Midpoints, Means, Medians and Statistical Significance (2013). Useful when you need to interpret responses and test whether differences are significant.
- How to interpret Ordinal Data: Median and Interquartile Range for Likert Scales (2014). Useful when you need to summarise responses using medians and interquartile ranges.
- Revisiting Likert scales, levels of measurement: a nuanced understanding (2014). Useful when you want to weigh the case for treating composite scales as interval data.
- How to summarise Likert scale data using SPSS (2014). Useful when you need to combine several items into a scale in SPSS.
- Dependent and independent variables, using SPSS, and minding one’s manners (2014). Useful when you need to tell variables apart and calculate correlations.
3. Researching multilingually
- Researching multilingually: More than meets the eye? (2014). Useful when your research setting involves more than one language and you want to think through what that means.
- Obtaining informed consent in a multilingual research setting (2014). Useful when you are unsure which language to use when inviting people to take part.
- Generating data in a multilingual research environment (2014). Useful when you need to decide which languages to use while generating data.
- Thinking about how to present multilingual data and Presenting multilingual data: Some options (2014). Useful when your data are in more than one language and you need to decide how to represent them in your report.
Looking for more?
For classroom-based research, observation and research ethics, see Resources for Research Literacy. For writing up and publishing your work, see Resources for Academic Writing.
By subscribing to this blog, you will receive occasional updates on topics relating to language education, including occasional posts on research methodology. (privacy policy)
About me
Achilleas Kostoulas is an applied linguist and language teacher educator at the Department of Primary Education, University of Thessaly, Greece. He holds a PhD and an MA in Teaching English to Speakers of Other Languages from the University of Manchester, UK and a BA in English Studies from the National and Kapodistrian University of Athens, Greece.
His research explores a wide range of issues connected with language (teacher) education, including language contact and plurilingualism, linguistic identities and ideologies, language policy and didactics, often using a Complex Dynamic Systems Theory perspective to tease out connections between them. Some of his work includes the research monograph The Intentional Dynamics of TESOL (2021, De Gruyter; with Juup Stelma) and the edited volume Doctoral Study and Getting Published (2025, Emerald; with Richard Fay), as well as numerous other publications.
Achilleas currently contributes to several projects that bring together his long-standing interests in language education, teacher development, and the social dimensions of language learning. As the coordinator of the AI Lang (Artificial Intelligence in Language Education) expert team at the European Centre for Modern Languages of the Council of Europe, he is active in developing principles and resources to help educators make informed, pedagogically grounded use of AI in their teaching. He also leads the University of Thessaly team of ReaLiTea (Research Literacy of Teachers), a project that supports language teachers to engage with, and contribute to, educational research. Alongside these, he contributes to LocalLing (Revitalisation of Linguistic Diversity and Cultural Heritage), a Horizon-funded initiative for the preservation of heritage and minority languages globally.
In addition to the above, Achilleas is the (co)editor-in-chief of the European Journal of Education and Language Review, and welcomes contributions that explore the dynamic intersections between language, education, and society.
About this post
This blog is a space for slow, reflective thinking about applied linguistics, language education, professional development, and the role of technology in language teaching and learning. Transparency about process, tools, and authorship is part of that commitment.
- I wrote this post on 23rd September 2026. I will periodically revise it to ensure accuracy, so feel free to point out any issues that come to your attention.
- When writing this post, I used artificial intelligence to support copy-editing and Search Engine Optimisation. I wrote the text, and retain responsibility for analytical thinking, authorial decisions and wording.
- The views expressed here are personal and do not necessarily reflect those of the University of Thessaly or any other entity with which I am affiliated.
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