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  • in reply to: GLMs in Commercial Property – any good reads? #5333
    SamCastillo
    Participant

      The exposure that you choose will make a big difference.  There are more potential variables than in life or health and so you need to use a variable selection algorithm.

      Take a look at our Free Exam PA study guide at Exam PA Dot Net without spaces.  This provides a conceptional overview for GLMs.  For property, read this paper that was published by the CAS: https://contentpreview.s3.us-east-2.amazonaws.com/CAS+Monograph+5+-+Generalized+Linear+Models+for+Insurance+Ratemaking.pdf

      in reply to: Copy the Results of a Summary Function Into Word #4948
      SamCastillo
      Participant

        Thanks!

        in reply to: Copy the Results of a Summary Function Into Word #4908
        SamCastillo
        Participant

          Still waiting

          in reply to: Copy the Results of a Summary Function Into Word #4266
          SamCastillo
          Participant

            Update: still waiting

            in reply to: Copy the Results of a Summary Function Into Word #4133
            SamCastillo
            Participant

              Good news – you’ll be able to copy and paste on the Prometric computers because they have an older version of the software.  The syllabus says

              The Prometric computers will have the 2016 versions of Microsoft Word and Excel, version 3.6.3 of R, and
              version 1.1.463 of RStudio.

              As a fix, just take screenshots using WINDOWS + SHFT + S and then copy into Word while you are practicing.  On your real exam, you will be able to copy the text.

              in reply to: Copy the Results of a Summary Function Into Word #4132
              SamCastillo
              Participant

                Please use this link instead of the above one:

                in reply to: Copy the Results of a Summary Function Into Word #4129
                SamCastillo
                Participant

                  Hi Joseph,

                  Great catch.  This is a major issue if the exam expects candidates to be able to do this quickly and it takes them longer.  I just sent an email to the SOA’s exam committee to notify them of this.  In earlier versions of Word, it would paste copied text using the same formatting as RStudio but in the latest version of Word it is no longer preserving the column widths.  I will reply here when they respond.  They usually reply within 2-3 business days.

                  Version Information:

                  Word version 2104

                  Rstudio version 1.4.1106

                  Enroll in our online course!  This exam is only a speed bump on your way to an ASA.  Learn concepts and strategies to pass.  We have 10 practice exams so that you can test your knowledge under exam conditions.  Compare good answers to great answers with over 33 hours of tutorials.  Reduce your study time by using 200 flashcards and 14 pages of cheat sheets to digest the critical info needed to pass.

                  Have a great day!

                  Sam Castillo

                  in reply to: Will be able to use ? on exam #3341
                  SamCastillo
                  Participant

                    Hi Porkins,

                    Yes, this works.  The ? is part of the R libraries which are installed on the Prometric computers.  There is no internet connection, but this is not needed because the files are local.

                    For example, here are a two of the useful references, which are included in our 14 pages of cheat sheets:

                    • ?family and ?make.link for GLMs.  This is useful when choosing the link function and response family for genaralized linear models.  The default arguments are the canonical links.
                    • ?stepAIC and ?AIC for formulas of the penalized log likelihoods.  Use this if you are unsure of whether a higher or lower AIC/BIC is better or worse.

                    Best regards,

                    Sam Castillo

                    Course Instructor at ExamPA.net

                    in reply to: Factors variables reading in as characters #3218
                    SamCastillo
                    Participant

                      Hi again Porkins,

                      Good questions.  You can get practice with these questions by enrolling in our online course – there are 9 practice exams and more than 135 practice questions.  Review your work quickly by watching video solutions.  This method has helped hundreds of actuaries to successfully pass.  This is the fastest way to study for this exam.

                      It’s great to be asking these questions now while there is still plenty of time to prepare.

                      “…it reads the factor variables in as character strings.  … why would I have to do that?”

                      This is a good programming question but is more info that you need to know for exam PA.  Characters are preferred when loading the data because there are only a finite number of factor levels possible whereas characters can have an unlimited number.  Otherwise there will be import errors.  The “tidyverse” library uses an improved version of the base R “data.frame” that removed the “stringAsFactors” argument.  All data should be imported as characters and then converted to factors after looking at the data dictionary.

                      “Does this happen in the real exam?”

                      Yes.  You will need to convert to factors manually.  Numeric variables also may be factors.  For example, I’m working on the solution to the December 7th 2020 exam that uses Bike Sharing, and the first question is exactly this: decide on which variables to convert to factors.

                      “Is this just the version of RStudio”

                      Good thought to check the software version.  This is a different thing entirely.  Rstudio is just the IDE and this is related to the R language itself (the engine under the hood of the IDE).  I just updated to RStudio v 1.4.1 this morning because I was getting an error where it would crash when calling the “library” function, so that’s always the first thing to check.

                      Does this answer your questions?

                      Best regards,

                      Sam Castillo

                      Course Instructor at ExamPA.net

                       

                      in reply to: how do i copy and paste a table In R for exam PA??? #3171
                      SamCastillo
                      Participant

                         

                        Best regards,

                        Sam Castillo

                        Course Instructor at ExamPA.net

                        in reply to: Exam PA general questions #2977
                        SamCastillo
                        Participant

                          Hi Michael,

                          It’s great to be thinking of this now so that you will be efficient in preparing.  Many people do not practice writing until the last months before the exam.

                          The past two exam sittings have had questions in the Specific Tasks that ask you to use non-technical language.  For example, in June of 2020, there was a question that asked you to summarise a data manipulation processing for your manager.  In the December 2019 exam, there was a question asking you to sell your model to a sales team.  The Executive Summary will always be non-technical.

                          There is no penalty for writing too much, but you can lose points for not writing enough.  This grading format favors longer reports.  2-2.5 pages single spaced, or 1,200 – 2,000 words is ideal.

                          After you do enough practice exams, you will be able to write more than you thought was originally possible.  We have 9 practice exams in our online course.  There are over 2 hours of tutorials about writing.  The length and number of words is not a good indicator of success because quality matters as much as quality.  Our spelling and grammar lessons give you confidence to craft perfect responses to every question.  Enroll today!

                          Best regards,

                          Sam Castillo

                          Course Instructor 

                           

                          in reply to: December 2019 Exam PA Questions #2882
                          SamCastillo
                          Participant

                            We just updated chapter 7.6 to tell you what to do about missing values.  This explains the different types of missingness and four strategies you can use to resolve them.

                             

                            in reply to: December 2019 Exam PA Questions #2814
                            SamCastillo
                            Participant

                              Hi Porkins,

                              You ask a great question.  Here is a screencast explantion.

                              Best regards,

                              Sam Castillo

                              Course Instructor at ExamPA.net

                              in reply to: Why use prune function #2606
                              SamCastillo
                              Participant

                                Hi Porkins,

                                Great question about decision trees that touches upon the way that you run code.  This can have a big impact on your exam report.  Here’s a screencast explanation.

                                Best regards,

                                Sam Castillo

                                Course Instructor at ExamPA.net

                                in reply to: How do I select a link function? #2048
                                SamCastillo
                                Participant

                                  Excellent question.

                                  Here’s a video explanation.

                                  There are two components that you need to take into consideration: the range of the response distribution and the range of the mean. Once the SOA’s modules are released in a few weeks, you will be able to review the chapters that cover this. By going through several examples of past exams, you can see why they justify each choice.  Almost every sitting of PA has included a GLM question. You also need to consider the interpretation – does it need to be easy to understand? What’s the canonical link function?

                                  If you enroll now you can get access to more than 28 hours of video tutorials. You can practice on realistic exams and then get feedback in real time. There are a number of lessons that cover these topics and in addition to the SOA’s answers, we also provide alternative answers.  There are often multiple correct ways of answering these questions as long as you can justify your reasons, which our examples cover.

                                  Best,

                                  Sam Castillo

                                  Course Instructor at ExamPA.net

                                  in reply to: Exam PA general questions #2046
                                  SamCastillo
                                  Participant

                                    Good question, Porkins.

                                    In all previous sittings, the Prometric staff have provided candidates with a printed project statement and so you can plan to use a pencil to underline sections or take notes.  There’s no algebra required so scratch paper is not needed.  Excel can be used as a calculator.  You can gain an advantage by building up your typing speed to 70 words per minute so that you’ll be able to write 20+ pages in your report.  Many people run out time before being able to write everything that they plan to.

                                    Best,

                                    Sam Castillo

                                    Course Instructor at ExamPA.net

                                  Viewing 16 posts - 1 through 16 (of 20 total)