1 Conjoint SDT

1. We use a python program developed by Anton Strezhnev (NYU) called Conjointsdt
2. Deals with several aspects of out CJ design
   • PHP script for randomization (external server)
   • JS script for randomization (only for Qualtrics)
   • Qualtrics HTML Tables
     
   • The survey design in R (in fact, it does not)

2 Attributes and Levels in Conjointsdt

3 Save the baseline design

1. Always save the design in case something get lost
2. File -> Save -> name_of_the_design.sdt

4 Choice-set

1. Edit -> Settings
2. Randomized Order of attributes per each respondent
   • That is, we keep the attribute order the same per each respondent
   • Ease the cognitive load
3. Use Weighted Randomization
   • Allow the usage of a specific marginal distribution for the levels
4. Number of Tasks
   • How many times a single respondents performs a CJ
5. Number of Profiles
   • Usually two Profile at time
   • Q: Can you think of a design where 3 profiles make sense?

5 Attribute order [Advanced]

1. Group together similar Attributes (e.g. all attributes related to Job in @hainmueller_causal_2014)
2. Usually, used in big designs to reduce the cognitive burden of the respondent
3. Edit -> Restrictions -> Attribute Order Constrains

6 Weights for different distribution of the attributes/level [Advanced]

1. File -> Randomization Weights
2. Impute the proportion from 0 to 1
3. If a levels appear 20% of the time, 0.20
4. The sum of the weights should be equal to 1
5. Rememberer to save: File -> Save -> name_of_the_design.sdt

7 Implement randomization restrictions [Advanced]

1. Q: Is it realistic that a candidate in its 30s has 20 years of political experience?
2. Set the conditional probability of displaying Age=30 AND Experience=20 equal to 0
3. Edit -> Restrictions -> Add Selected levels to Restriction
4. Rememberer to save: File -> Save -> name_of_the_design.sdt

8 Exporting

1. Menu -> Edit -> Export to PHP
   • This is going to be on a server for the randomization
   • php_script_name_of_the_design.php
2. Menu -> Edit -> Export to Java Script
   • This is going to be directly on Qualtrics
   • php_script_name_of_the_design.js
3. Menu -> Edit -> Export to Qualtrics
   • HTML tables that will be fed by the PHP/JS
   • Task_1_name_of_the_design.html
4. Menu -> Edit -> Export to R
   • Used in the Modelling Part
   • design_R_name_of_the_design.dat