Important: Read this before posting to this forum

  1. This forum is for questions related to the use of Apollo. We will answer some general choice modelling questions too, where appropriate, and time permitting. We cannot answer questions about how to estimate choice models with other software packages.
  2. There is a very detailed manual for Apollo available at http://www.ApolloChoiceModelling.com/manual.html. This contains detailed descriptions of the various Apollo functions, and numerous examples are available at http://www.ApolloChoiceModelling.com/examples.html. In addition, help files are available for all functions, using e.g. ?apollo_mnl
  3. Before asking a question on the forum, users are kindly requested to follow these steps:
    1. Check that the same issue has not already been addressed in the forum - there is a search tool.
    2. Ensure that the correct syntax has been used. For any function, detailed instructions are available directly in Apollo, e.g. by using ?apollo_mnl for apollo_mnl
    3. Check the frequently asked questions section on the Apollo website, which discusses some common issues/failures. Please see http://www.apollochoicemodelling.com/faq.html
    4. Make sure that R is using the latest official release of Apollo.
  4. If the above steps do not resolve the issue, then users should follow these steps when posting a question:
    1. provide full details on the issue, including the entire code and output, including any error messages
    2. posts will not immediately appear on the forum, but will be checked by a moderator first. This may take a day or two at busy times. There is no need to submit the post multiple times.

Search found 13 matches

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by psalazar
02 Mar 2023, 01:38
Forum: Post-estimation analysis/use of results
Topic: Internal validity & Root likelihood (RLH) test
Replies: 2
Views: 3029

Re: Internal validity & Root likelihood (RLH) test

Many thanks, Stephane!

Best wishes,

Pamela.
by psalazar
02 Mar 2023, 01:35
Forum: Post-estimation analysis/use of results
Topic: Bootstrap estimation
Replies: 7
Views: 4548

Re: Bootstrap estimation

Hi Stephane, Many thanks for your response. I am running bootstrap estimations because to determine the relative “weight” of the attributes, I calculated relative scores, and I want to obtain a 95% confidence interval around each of them. I am following these two papers: -Genie, M.G., Ryan, M., &...
by psalazar
11 Feb 2023, 04:56
Forum: Post-estimation analysis/use of results
Topic: Post-estimation scenario analysis
Replies: 1
Views: 2900

Post-estimation scenario analysis

Dear Stephane and David, I run a couple of mixed logit models in which I asked respondents to choose between two unlabelled alternatives (i.e. Programme A vs Programme B), described by 6 attributes (each one with 3 levels). Now that I have the results, I would like to run a post-estimation scenario ...
by psalazar
08 Feb 2023, 15:49
Forum: Post-estimation analysis/use of results
Topic: Internal validity & Root likelihood (RLH) test
Replies: 2
Views: 3029

Internal validity & Root likelihood (RLH) test

Dear all, After running some mixed logit models, I would like to conduct a root likelihood (RLH) test to check for the consistency of the responses. This is, following: -Jonker et al (2022) The Sensitivity and Specificity of Repeated and Dominant Choice Tasks in Discrete Choice Experiments. Value in...
by psalazar
08 Feb 2023, 15:23
Forum: Post-estimation analysis/use of results
Topic: Bootstrap estimation
Replies: 7
Views: 4548

Re: Bootstrap estimation

Hi Stephane,

Many thanks!

May I ask you for suggestions when using bootstrap estimation with mixed logits? each model is taking various days to run.

Best wishes,

Pamela.
by psalazar
08 Feb 2023, 15:21
Forum: Errors during model validation and/or estimation.
Topic: Aapollo_saveOutput: Error in paste0(rep(...
Replies: 3
Views: 1236

Re: Aapollo_saveOutput: Error in paste0(rep(...

Hi Stephane, Many thanks! I found the solution. I was getting the error also with the on-screen output, and solved it by treating all variables as categorical. Checking for potential correlation between attributes has been challenging as my experimental design did not fully account for it (ended up ...
by psalazar
14 Dec 2022, 10:35
Forum: Errors during model validation and/or estimation.
Topic: Aapollo_saveOutput: Error in paste0(rep(...
Replies: 3
Views: 1236

Aapollo_saveOutput: Error in paste0(rep(...

Dear all, I am estimating a simple MNL with two interaction terms (code below).I have no problems running the code, but when I ask Apollo to save it (apollo_saveOutput(model)), I get the following error: Error in paste0(rep(" ", max(nchar(m)) - nchar(m)), m, collapse = "") : resu...
by psalazar
06 Dec 2022, 17:45
Forum: Post-estimation analysis/use of results
Topic: Bootstrap estimation
Replies: 7
Views: 4548

Bootstrap estimation

Dear all, I ran my MNL models and would like to use bootstrap estimation. I checked the Apollo manual (pp. 129), but I don't know how to add the bootstrap_settings (nRep) option to use 1000 bootstrap samples (default is 30). Could you please give me an example (code syntax)? Many thanks! Best wishes...
by psalazar
12 Oct 2022, 07:25
Forum: Errors during model validation and/or estimation.
Topic: Joint estimation on two SP datasets. Error: Duplicated componentName found
Replies: 3
Views: 1819

Re: Joint estimation on two SP datasets. Error: Duplicated componentName found

Thank you, Stephane!

Best wishes,

Pamela.
by psalazar
08 Oct 2022, 12:18
Forum: Errors during model validation and/or estimation.
Topic: Joint estimation on two SP datasets. Error: Duplicated componentName found
Replies: 3
Views: 1819

Joint estimation on two SP datasets. Error: Duplicated componentName found

Hi Stephane, I am pooling data from two designs: -Design 1 has 6 attributes -Design 2 has the same attributes as Design 1, except for the last one "cost" (i.e. using only 5 attributes) In my dataset, I have two binary variables to indicate Apollo which dataset I'm using: "Done" f...

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