I am working on an analysis where I would like to know whether an intervention acts differently across levels of income (5 levels total). I'd like to do this for females only, and adjust for age. In the end, I'd like to obtain an odds ratio for each of the 5 levels of income, comparing the treatment to the control. Here is what I have so far:
PROC LOGISTIC data=trial;
WHERE Intervention>. and Income>. and Age>. and Outcome>. AND Sex=0;
CLASS Income (ref='5') Age (ref='5') / param=ref;
MODEL Outcome(EVENT='1')=Intervention Income Age Intervention*Income / expb;
RUN;
This gets me an OR for the first 4 levels of income, but not the reference group. I feel like I should be using a contrast statement or something like that, but I can't seem to figure it out.
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I am trying to build a content based recommendation model but I am stuck on how to proceed with which algorithm to choose from. Basically, my features are user_id, user_age, gender, location, show_id, show_type(eg: series, movies etc.), show_duration, user_watched_duration, genre, rating. And my model has to predict top 5 recommendation shows for certain users.
The proportion of users to shows is hugh. Like there are only around 10k users but the shows that are mapped to each user is approx 150. So each user has an history of 150 shows mapped to them on an average. So total records are 10k x 150 = 15,00,000
Now, I am confused like which algorithm to proceed with this scenario. I read content based method is the ideal for my scenario. But when I checked SVD from surprise library, it is only taking 3 features as input DataSet - "user_id", "item_id", "rating" and fitting the model. But I have to consider fitting other features like user_watched_duration out of the show_duration and give preference if he/she has fully watched the show. And similarly, I want the model to consider recommending based on the Gender and age also. Like for example, for young men, (male < 20 years old) have watched a show and given a higher rating, then my recommendation to user's of similar category of young men should be given.
Can I use to train a normal classifical model like KNN for this? I tried to think of using sparse matrix using csr_matrix with row consisting of user_id and col consisting of show_id. And then transposing using (user_show_matrix.T * user_show_matrix) , so that I can use this to get counts of shows watched for that particular user. But the problem with this approach is that I cannot map other features with this, right?
So please suggest how to proceed. I already did data cleaning, label encoded categories etc. Will I be able to use any classification algorithms for this? Appreciate any references on similar approaches. Thank you!
The problem I would like to solve is how to choose the best seats on a train based on some ordered user preferences. eg. whether they'd like a seat facing forwards, backwards (or don't care), whether they'd like a seat at a table or not, whether they need to be near a toilet, luggage rack, buffet car, near the door. Window / Aisle seat. Whether they want the aisle to the left or the right (can be very important some someone with a stuff knee!).
Most customers will specify one or two preferences, other may specify more. For some, being near the toilet might be the most important factor, for others having that table to work at might be the most important.
There may be more than one passenger (although they will share preferences). These should be sat as close to each other as possible. 2 passengers would ideally be sat next to each other, or opposite each other at a table seat. A group of 8 passengers might best be split into 2 groups of 4 or 4 groups of 2...
Position is defined by carriage number (seats in the same carriage are better then seats in different carriages) and by x/y coordinate within that carriage - so easy enough to calculate distance between any pair of seats - but a BIG job to calculate distances between EVERY pair of seats...)
Each [available] seat (pre-filtered by ticket class) will have the above attributes either defined or set to NULL (for unknown - seat facing is often unknown).
So for training I can provide a vast array of example trains and customer preferences with the best balance of preferences version position.
For execution I want to provide a run-time specific array of seats with attributes, a set of user preferences and a set if weighting for those preference (eg. passenger 1 thinks being near toilet is most important, passenger 2 think having a table is most important, passenger 3 think being in the quiet carriage is..) and finally the number of passengers.
Output will be an array of seats (one per passenger) that strike the best compromise between matching as many customer preferences as possible (usually not possible to match all preferences) and keeping the seats fairly close to each other.
eg. We might be able to match 2 preferences with seats 2 rows apart, but match 3 preference with seats 10 rows apart...
Obviously distance will need a weighting the same as the individual preference and necessary to choose between those two. I suppose a distance not greater than X becomes just one more customer preference...
I've not done any ML work before, so it's all going to be a learning exercise for me. I wish I had the time to just play and see what comes out, but I don't, Happy to do that, but I need to have a reasonable expectation of a positive result otherwise I'll have to focus on a more traditional approach. Limited time and all that...
So, my questions are:
Is this a suitable problem for machine learning?
If so, is brain.js a good choice, or is something else more suitable? AWS ML service perhaps?
Any advice on how to organise all my data into something suitable for an ML engine to process?
Machine Learning is good at finding hidden patterns in complex data. In your case, you would need a lot of data where user preferences are already matched with optimal seating arrangements.
You could then try to see if the ML model can actually make optimal seating arrangements by itself. It’s an interesting problem but it may also lead to unexpected seating :)
If you don’t have training data you could collect it live, by registering where people sit down, knowing their preferences.
What is generally considered the correct approach when you are performing a regression and your training data contains 'incidents' of some sort, but there may be a varying number of these items per training line?
To give you an example - suppose I wanted to predict the likelihood of accidents on a number of different roads. For each road, I may have a history multiple accidents and each accident will have its own different attributes (date (how recent), number of casualties, etc). How does one encapsulate all this information on one line?
You could for example assume a maximum of (say) ten and include the details of each as a separate input (date1, NoC1, date2, NoC2, etc....) but the problem is we want each item to be treated similarly and the model will treat items in column 4 as fundamentally separate from those in column 2 above, which it should not.
Alternatively we could include one row for each incident, but then any other columns in each row which are not related to these 'incidents' (such as age of road, width, etc) will be included multiple times and hence produce bias in the results.
What is the standard method that is use to accomplish this?
Many thanks
I'm looking for a machine learning method to recognize input ranges that result customer dissatisfaction.
For instance, assume that we have a database of customer's age, customer's gender, date and time that customer stops by, person who is in charge of providing service to customer, etc. and finally a number in range of 0 to 10 which stands for customer satisfaction (Extracted from customer's feedback).
Now I'm looking for a method to determine input ranges which results dissatisfaction. For example male customers who are stopping by John, between 10-12pm are mainly dissatisfied.
I believe there already is a kind of clustering or neural network method for this purpose. Could you help me?
This is not a clustering problem. You have training data.
Instead, you may be looking for a decision tree.
There is more than one method to do it (correlation analysis for ex.)
One simple way is to classify your data by the degree of satisfaction (target)
Classes:
0-5 DISSATISFIED
6-10 SATISFIED
Than look for repetition along features in each cluster.
For example:
if you are interested by one feature, ex: the person who stopped clients, than just get the most frequent name within the two classes to get a result like 80% of unsatisfied client was stopped by jhon
if you are interested by more than one feature, ex: the person who stopped the client AND the time of the day, in this case you can consider the couple of features us one and do the same thing as the first case, than you will get something like 30% of unsatisfied client was stopped by jhon between 10 and 11 am
What do you want to know? Which service person to fire, what are the best hours to provide the service, or sth. else? I mean what are your classes?
Provided, you what to evaluate the service person - the classes are the
persons. In SVM (and I think for NN applies the same) I would split all not purely numerical data in boolean attributes.
Age: unchanged, number
Gender: male 1/0, female 1/0
Date: 7 features for days of week, possibly the number of experience days of the service person. for each special date an attribute e.g. national holiday 1/0
Time: split the time-span in reasonable ranges e.g. 15 min. Each range is a feature
Satisfaction: unchanged - number 1-10
With this model you could predict the satisfaction index for each service person for given date, time, gender, age.
I guess, you can try using anomaly detection algorithms. Basically if you consider the satisfaction level as the dependent variable, then you can try to find the samples which are located away from the majority of the samples in the euclidean space. These away samples could signify dissatisfaction.
I posted question on stat stack exchange but unfortunately got no answer so far, so I clone it here and do hope someone can help.
I'm newbie in machine learning. Recently I tried to learn something on this and got following concern:
I have products classed by categories. Also I have users with gender and device model information.
First, I made a chi square test to check whether categories and gender + device information are associated. For example, my p-value is 0.000012 so I stated that the user (gender + device) is associated with categories.
So if a new user come with his gender (Female) + device (iPhone):
As the chi square test result, there should be an association between gender + device and categories. So I select top 10 categories that were consumed by Female who using iPhone. I've got the list, e.g. [1. Fashion, 2. Mobile devices 3. Cameras, 4. Home furnitures, 5. Bikes, etc.]
I also make a z-test on categories (without any user information), and got the list (higher z-score will be on top), e.g. [1. Mobile devices, 2. Bikes, 3. Fashion, 4. Laptops, etc.]
So in this case, which list should I give to that user? Or any possibility to combine them? Or did I do something wrong?
Thanks in advance :-)
Strictly speaking, none of the tests is appropriate. In both tests you have a null hypothesis (that gender and model is not related to category), and you are trying to find the probability that this hypothesis is wrong. However, theses two tests are parametric tests, that is for the results to be correct you have to know that the probability follows a specific distribution (chi square and normal distributions respectively). In your case you can make no such assumption, so the tests are not suitable. If you want to use significance tests, you should use a non-parametric tests, Wilcoxon and Friedman tests being the most common. However, significance tests are usually used after the problem has been solved to check if the results achieved can be attributed to luck. They are not used to solve the problem.
If you want to find correlation between gender, model and category, you should use some correlation coefficient, such as Pearson correlation and intraclass correlation. However, you have not described your data in detail, so I'm not sure what you are trying to achieve. Based on gender and model only, probably the safest and simplest thing you can do is return the most visited categories (number of occurences) by women who use iPhone.