Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Supported by

LMM in JASP: factor coding


I have ventured lmm with JASP: it is absolutely amazing!

But I have a question about factor coding. As far as I know, it is a dummy coding. How does it specify the contrasts of a factor with 3 levels (say, color: red, blue and green)? I run a full model of a such a factor + several continious (say, age) and categorical variables (luckily with only 2 levels:), say, gender), and the outcome shows me the following:

Color (1) Estimate SE...etc

Color (2) Estimate SE etc....

Color (1) * Age Estimate SE etc...

Color (2) * Age Estimate SE etc...

Color (1) * Gender Estimate SE etc...

How do I interpret Color (1) and Color (2) and the respective interactions? What is compared to what?

Many thanks for your help!


  • Hi Katharina,

    happy to hear about your positive experience!

    The analysis uses sum contrast coding for categorical (nominal / factors, ordinal) predictors (in contrast to R which uses dummy encoding by default). This scheme is used for better interpretability of models with interactions. However, the fixed and random effects estimates will differ from those obtained from R with default settings. We advise using the 'Estimated marginal means' section for obtaining mean estimates at individual factor levels. For comparing the mean estimates, you can use the contrasts option.

    For example, if you are interested in the mean estimates of different colors, you can add the Color variable into 'Selected variables' box in 'Estimated marginal means'. Similarly, you can add the Gender variable as well and obtain mean estimates for each combination of Gender and Color. If you want to compare those estimates, you can click on 'Specify contrasts' and set the comparisions you are interested in. Setting .5 for one of the colors and -.5 for another one will create a test for the difference between estimated means of each color.



  • edited October 2020

    Thank you for your quick answer. This is all clear. I still do not understand what

    Color (1) Estimate SE...etc

    Color (2) Estimate SE etc...

    would mean

    Is Color (1) and Color (2) - a contrast between all and red and blue or something else? Beacuse usually you would then have Color1, Color 2 and Color 3, if you compare to grand mean?

    How should I interpret that: Color (1) had a significant effect on Y. But what is Color (1)?

  • If you have a factor with more than two levels (such as your color) our recommendation is that you do not interpret the estimates of the model directly (so to answer your question: you don't). This holds for both the classical (which I assume you have used) and Bayesian LMMs.

    Instead, you (a) inspect the omnibus test. If they show a (say) significant interaction of color and age you do (b) what Frantisek suggests and use either the 'Estimated marginal means' functionality or the 'Estimated trends' option. The former allows you to test for the effect of color for different values of age whereas the later allows you to look at the different slopes of age for the different colors.

  • Ok, thank you!

    It does get complicated when one has many factors :)

    But so I thought...

Sign In or Register to comment.

agen judi bola , sportbook, casino, togel, number game, singapore, tangkas, basket, slot, poker, dominoqq, agen bola. Semua permainan bisa dimainkan hanya dengan 1 ID. minimal deposit 50.000 ,- bonus cashback hingga 10% , diskon togel hingga 66% bisa bermain di android dan IOS kapanpun dan dimana pun. poker , bandarq , aduq, domino qq , dominobet. Semua permainan bisa dimainkan hanya dengan 1 ID. minimal deposit 10.000 ,- bonus turnover 0.5% dan bonus referral 20%. Bonus - bonus yang dihadirkan bisa terbilang cukup tinggi dan memuaskan, anda hanya perlu memasang pada situs yang memberikan bursa pasaran terbaik yaitu Bola168. Situs penyedia segala jenis permainan poker online kini semakin banyak ditemukan di Internet, salah satunya TahunQQ merupakan situs Agen Judi Domino66 Dan BandarQ Terpercaya yang mampu memberikan banyak provit bagi bettornya. Permainan Yang Di Sediakan Dewi365 Juga sangat banyak Dan menarik dan Peluang untuk memenangkan Taruhan Judi online ini juga sangat mudah . Mainkan Segera Taruhan Sportbook anda bersama Agen Judi Bola Bersama Dewi365 Kemenangan Anda Berapa pun akan Terbayarkan. Tersedia 9 macam permainan seru yang bisa kamu mainkan hanya di dalam 1 ID saja. Permainan seru yang tersedia seperti Poker, Domino QQ Dan juga BandarQ Online. Semuanya tersedia lengkap hanya di ABGQQ. Situs ABGQQ sangat mudah dimenangkan, kamu juga akan mendapatkan mega bonus dan setiap pemain berhak mendapatkan cashback mingguan. ABGQQ juga telah diakui sebagai Bandar Domino Online yang menjamin sistem FAIR PLAY disetiap permainan yang bisa dimainkan dengan deposit minimal hanya Rp.25.000. DEWI365 adalah Bandar Judi Bola Terpercaya & resmi dan terpercaya di indonesia. Situs judi bola ini menyediakan fasilitas bagi anda untuk dapat bermain memainkan permainan judi bola. Didalam situs ini memiliki berbagai permainan taruhan bola terlengkap seperti Sbobet, yang membuat DEWI365 menjadi situs judi bola terbaik dan terpercaya di Indonesia. Tentunya sebagai situs yang bertugas sebagai Bandar Poker Online pastinya akan berusaha untuk menjaga semua informasi dan keamanan yang terdapat di POKERQQ13. Kotakqq adalah situs Judi Poker Online Terpercayayang menyediakan 9 jenis permainan sakong online, dominoqq, domino99, bandarq, bandar ceme, aduq, poker online, bandar poker, balak66, perang baccarat, dan capsa susun. Dengan minimal deposit withdraw 15.000 Anda sudah bisa memainkan semua permaina pkv games di situs kami. Jackpot besar,Win rate tinggi, Fair play, PKV Games