Re: Is Mahout the right tool to recommend cross sales?

2013-04-11 Thread Sean Owen
This sounds like just a most-similar-items problem. That's good news
because that's simpler. The only question is how you want to compute
item-item similarities. That could be based on user-item interactions.
If you're on Hadoop, try the RowSimilarityJob (where you will need
rows to be items, columns the users).

On Thu, Apr 11, 2013 at 6:11 PM, Billy b...@ntlworld.com wrote:
 I am very new to Mahout and currently just ready up to chapter 5 of 'MIA'
 but after reading about the various User centric and Item centric
 recommenders they all seem to still need a userId so still unsure if Mahout
 can help with a fairly common recommendation.

 My requirement is to produce 'n' item recommendations based on a chosen
 item.

 E.g. if I've added item #1 to my order then based on all the
 other items; in all the other orders for this site, what are the
 likely items that I may also want add to my order based; on the item to
 item relationship in the history of orders of this site?

 Most probably using the most popular relationship between the item I have
 chosen and all the items in all the other orders.

 My data is not 'user' specific; and I don't think it should be, but more
 like order specific as its the pattern of items in each order that should
 determine the recommendation.

 I have no preference values so merely boolean preferences will be used.

 If Mahout can perform these calculations then how must I present the data?

 Will I need to shape the data in some way to feed into Mahout (currently
 versed in using Hadoop via Aws Emr using Java)

 Thanks for the advice in advance,

 Billy


Re: Is Mahout the right tool to recommend cross sales?

2013-04-11 Thread Pat Ferrel
Or you may want to look at recording purchases by user ID. Then use the 
standard recommender to train on (userID, itemsID, boolean). Then query the 
trained recommender thus: recommender.mostSimilarItems(long itemID, int 
howMany) This does what you want but uses more data than just what items were 
purchased together, sound like a shopping-cart recommender.

On Apr 11, 2013, at 10:28 AM, Sean Owen sro...@gmail.com wrote:

This sounds like just a most-similar-items problem. That's good news
because that's simpler. The only question is how you want to compute
item-item similarities. That could be based on user-item interactions.
If you're on Hadoop, try the RowSimilarityJob (where you will need
rows to be items, columns the users).

On Thu, Apr 11, 2013 at 6:11 PM, Billy b...@ntlworld.com wrote:
 I am very new to Mahout and currently just ready up to chapter 5 of 'MIA'
 but after reading about the various User centric and Item centric
 recommenders they all seem to still need a userId so still unsure if Mahout
 can help with a fairly common recommendation.
 
 My requirement is to produce 'n' item recommendations based on a chosen
 item.
 
 E.g. if I've added item #1 to my order then based on all the
 other items; in all the other orders for this site, what are the
 likely items that I may also want add to my order based; on the item to
 item relationship in the history of orders of this site?
 
 Most probably using the most popular relationship between the item I have
 chosen and all the items in all the other orders.
 
 My data is not 'user' specific; and I don't think it should be, but more
 like order specific as its the pattern of items in each order that should
 determine the recommendation.
 
 I have no preference values so merely boolean preferences will be used.
 
 If Mahout can perform these calculations then how must I present the data?
 
 Will I need to shape the data in some way to feed into Mahout (currently
 versed in using Hadoop via Aws Emr using Java)
 
 Thanks for the advice in advance,
 
 Billy



Re: Is Mahout the right tool to recommend cross sales?

2013-04-11 Thread Sebastian Schelter
Use ItemSimilarityJob instead of RowSimilarityJob, its the easy-to-use
wrapper around that :)

On 11.04.2013 19:28, Sean Owen wrote:
 This sounds like just a most-similar-items problem. That's good news
 because that's simpler. The only question is how you want to compute
 item-item similarities. That could be based on user-item interactions.
 If you're on Hadoop, try the RowSimilarityJob (where you will need
 rows to be items, columns the users).
 
 On Thu, Apr 11, 2013 at 6:11 PM, Billy b...@ntlworld.com wrote:
 I am very new to Mahout and currently just ready up to chapter 5 of 'MIA'
 but after reading about the various User centric and Item centric
 recommenders they all seem to still need a userId so still unsure if Mahout
 can help with a fairly common recommendation.

 My requirement is to produce 'n' item recommendations based on a chosen
 item.

 E.g. if I've added item #1 to my order then based on all the
 other items; in all the other orders for this site, what are the
 likely items that I may also want add to my order based; on the item to
 item relationship in the history of orders of this site?

 Most probably using the most popular relationship between the item I have
 chosen and all the items in all the other orders.

 My data is not 'user' specific; and I don't think it should be, but more
 like order specific as its the pattern of items in each order that should
 determine the recommendation.

 I have no preference values so merely boolean preferences will be used.

 If Mahout can perform these calculations then how must I present the data?

 Will I need to shape the data in some way to feed into Mahout (currently
 versed in using Hadoop via Aws Emr using Java)

 Thanks for the advice in advance,

 Billy



Re: Is Mahout the right tool to recommend cross sales?

2013-04-11 Thread Sean Owen
You can try treating your orders as the 'users'. Then just compute
item-item similarities per usual.

On Thu, Apr 11, 2013 at 7:59 PM, Billy b...@ntlworld.com wrote:
 Thanks for replying,


 I don't have users, well I do :-) but in this case it should not influence
 the recommendations

 ,
 these need to be based on the relationship between
 
 items ordered with other items
 in the 'same order'
 .

 E.g. If item #1 has been order with item #4

 [
 22
 ]
 times and item #1 has been order with item #9
 [
 57
 ]
 times then
 if I added item #1 to my order
 these would both be recommended
 but item #9 would be recommended above item #4 purely based on the fact that
 the relationship between item #1 and item #9 is greater than the
 relationship with item #4.

 What I don't want is; if a user ordered items #A, #B, #C separately
 'at some point in their order history' then recommen
 d #A and #C to other users who order #B ... I still don't want this if the
 items are similar and/or the users similar.

 Cheers

 Billy



 On 11 Apr 2013 18:28, Sean Owen sro...@gmail.com wrote:

 This sounds like just a most-similar-items problem. That's good news
 because that's simpler. The only question is how you want to compute
 item-item similarities. That could be based on user-item interactions.
 If you're on Hadoop, try the RowSimilarityJob (where you will need
 rows to be items, columns the users).

 On Thu, Apr 11, 2013 at 6:11 PM, Billy b...@ntlworld.com wrote:
  I am very new to Mahout and currently just ready up to chapter 5 of
  'MIA'
  but after reading about the various User centric and Item centric
  recommenders they all seem to still need a userId so still unsure if
  Mahout
  can help with a fairly common recommendation.
 
  My requirement is to produce 'n' item recommendations based on a chosen
  item.
 
  E.g. if I've added item #1 to my order then based on all the
  other items; in all the other orders for this site, what are the
  likely items that I may also want add to my order based; on the item to
  item relationship in the history of orders of this site?
 
  Most probably using the most popular relationship between the item I
  have
  chosen and all the items in all the other orders.
 
  My data is not 'user' specific; and I don't think it should be, but more
  like order specific as its the pattern of items in each order that
  should
  determine the recommendation.
 
  I have no preference values so merely boolean preferences will be used.
 
  If Mahout can perform these calculations then how must I present the
  data?
 
  Will I need to shape the data in some way to feed into Mahout (currently
  versed in using Hadoop via Aws Emr using Java)
 
  Thanks for the advice in advance,
 
  Billy


Re: Is Mahout the right tool to recommend cross sales?

2013-04-11 Thread Ted Dunning
Actually, making this user based is a really good thing because you get
recommendations from one session to the next.  These may be much more
valuable for cross-sell than things in the same order.


On Thu, Apr 11, 2013 at 12:50 PM, Sean Owen sro...@gmail.com wrote:

 You can try treating your orders as the 'users'. Then just compute
 item-item similarities per usual.

 On Thu, Apr 11, 2013 at 7:59 PM, Billy b...@ntlworld.com wrote:
  Thanks for replying,
 
 
  I don't have users, well I do :-) but in this case it should not
 influence
  the recommendations
 
  ,
  these need to be based on the relationship between
  
  items ordered with other items
  in the 'same order'
  .
 
  E.g. If item #1 has been order with item #4
 
  [
  22
  ]
  times and item #1 has been order with item #9
  [
  57
  ]
  times then
  if I added item #1 to my order
  these would both be recommended
  but item #9 would be recommended above item #4 purely based on the fact
 that
  the relationship between item #1 and item #9 is greater than the
  relationship with item #4.
 
  What I don't want is; if a user ordered items #A, #B, #C separately
  'at some point in their order history' then recommen
  d #A and #C to other users who order #B ... I still don't want this if
 the
  items are similar and/or the users similar.
 
  Cheers
 
  Billy
 
 
 
  On 11 Apr 2013 18:28, Sean Owen sro...@gmail.com wrote:
 
  This sounds like just a most-similar-items problem. That's good news
  because that's simpler. The only question is how you want to compute
  item-item similarities. That could be based on user-item interactions.
  If you're on Hadoop, try the RowSimilarityJob (where you will need
  rows to be items, columns the users).
 
  On Thu, Apr 11, 2013 at 6:11 PM, Billy b...@ntlworld.com wrote:
   I am very new to Mahout and currently just ready up to chapter 5 of
   'MIA'
   but after reading about the various User centric and Item centric
   recommenders they all seem to still need a userId so still unsure if
   Mahout
   can help with a fairly common recommendation.
  
   My requirement is to produce 'n' item recommendations based on a
 chosen
   item.
  
   E.g. if I've added item #1 to my order then based on all the
   other items; in all the other orders for this site, what are the
   likely items that I may also want add to my order based; on the item
 to
   item relationship in the history of orders of this site?
  
   Most probably using the most popular relationship between the item I
   have
   chosen and all the items in all the other orders.
  
   My data is not 'user' specific; and I don't think it should be, but
 more
   like order specific as its the pattern of items in each order that
   should
   determine the recommendation.
  
   I have no preference values so merely boolean preferences will be
 used.
  
   If Mahout can perform these calculations then how must I present the
   data?
  
   Will I need to shape the data in some way to feed into Mahout
 (currently
   versed in using Hadoop via Aws Emr using Java)
  
   Thanks for the advice in advance,
  
   Billy



Re: Is Mahout the right tool to recommend cross sales?

2013-04-11 Thread Billy
As in the example data 'intro.csv' in the MIA it has users 1-5 so if I ask
for recommendations for user 1 then this works but if I ask for
recommendations for user 6 (a new user yet to be added to the data model)
then I get no recommendations ... so if I substitute users for orders then
again I will get no recommendations ... which I sort of understand so do I
need to inject my 'new' active order; along with its attached item/s into
the data model first and then ask for the recommendations for the order by
offering up the new orderId? or is there a way of merely offering up an
'item' and then getting recommendations based merely on the item using the
data already stored and the relationships with my item?

My assumptions:
#1
I am assuming the data model is a static island of data that has been
processed (flattened) overnight (most probably by an Hadoop process) due to
the size of this data ... rather than a living document that is updated as
soon as new data is available.
#2
I'm also assuming that instead of reading in the data model and
providing recommendations 'on the fly' I will have to run thru every item
in my catalogue and find out the top 5 recommended items that are ordered
with each item (most probably via a Hadoop process) and then store this
output in dynamoDb or luncene for quick access.

Sorry for all the questions but it such an interesting subject.


On 11 April 2013 22:04, Ted Dunning ted.dunn...@gmail.com wrote:

 Actually, making this user based is a really good thing because you get
 recommendations from one session to the next.  These may be much more
 valuable for cross-sell than things in the same order.


 On Thu, Apr 11, 2013 at 12:50 PM, Sean Owen sro...@gmail.com wrote:

 You can try treating your orders as the 'users'. Then just compute
 item-item similarities per usual.

 On Thu, Apr 11, 2013 at 7:59 PM, Billy b...@ntlworld.com wrote:
  Thanks for replying,
 
 
  I don't have users, well I do :-) but in this case it should not
 influence
  the recommendations
 
  ,
  these need to be based on the relationship between
  
  items ordered with other items
  in the 'same order'
  .
 
  E.g. If item #1 has been order with item #4
 
  [
  22
  ]
  times and item #1 has been order with item #9
  [
  57
  ]
  times then
  if I added item #1 to my order
  these would both be recommended
  but item #9 would be recommended above item #4 purely based on the fact
 that
  the relationship between item #1 and item #9 is greater than the
  relationship with item #4.
 
  What I don't want is; if a user ordered items #A, #B, #C separately
  'at some point in their order history' then recommen
  d #A and #C to other users who order #B ... I still don't want this if
 the
  items are similar and/or the users similar.
 
  Cheers
 
  Billy
 
 
 
  On 11 Apr 2013 18:28, Sean Owen sro...@gmail.com wrote:
 
  This sounds like just a most-similar-items problem. That's good news
  because that's simpler. The only question is how you want to compute
  item-item similarities. That could be based on user-item interactions.
  If you're on Hadoop, try the RowSimilarityJob (where you will need
  rows to be items, columns the users).
 
  On Thu, Apr 11, 2013 at 6:11 PM, Billy b...@ntlworld.com wrote:
   I am very new to Mahout and currently just ready up to chapter 5 of
   'MIA'
   but after reading about the various User centric and Item centric
   recommenders they all seem to still need a userId so still unsure if
   Mahout
   can help with a fairly common recommendation.
  
   My requirement is to produce 'n' item recommendations based on a
 chosen
   item.
  
   E.g. if I've added item #1 to my order then based on all the
   other items; in all the other orders for this site, what are the
   likely items that I may also want add to my order based; on the item
 to
   item relationship in the history of orders of this site?
  
   Most probably using the most popular relationship between the item I
   have
   chosen and all the items in all the other orders.
  
   My data is not 'user' specific; and I don't think it should be, but
 more
   like order specific as its the pattern of items in each order that
   should
   determine the recommendation.
  
   I have no preference values so merely boolean preferences will be
 used.
  
   If Mahout can perform these calculations then how must I present the
   data?
  
   Will I need to shape the data in some way to feed into Mahout
 (currently
   versed in using Hadoop via Aws Emr using Java)
  
   Thanks for the advice in advance,
  
   Billy





Re: Is Mahout the right tool to recommend cross sales?

2013-04-11 Thread Sean Owen
You can actually create a user #6 for your new order. Or you can use
the anonymous user function of the library, although it's hacky.

We may be mixing up terms here. DataModel is a class that has
nothing to do with Hadoop. Hadoop in turn has no part in real-time
anything, like recommending to a brand-new user. However it could
build an offline model of item-item similarities and you could do
something like a most-similar-items computation for a given new basket
of goods. That is effectively what the anonymous user function is
doing anyway.

You can precompute all recommendations for all items but that's a lot
of work! It's easy to get away with it with a thousand items, but with
a million this may be infeasibly slow.

On Thu, Apr 11, 2013 at 10:38 PM, Billy b...@ntlworld.com wrote:
 As in the example data 'intro.csv' in the MIA it has users 1-5 so if I ask
 for recommendations for user 1 then this works but if I ask for
 recommendations for user 6 (a new user yet to be added to the data model)
 then I get no recommendations ... so if I substitute users for orders then
 again I will get no recommendations ... which I sort of understand so do I
 need to inject my 'new' active order; along with its attached item/s into
 the data model first and then ask for the recommendations for the order by
 offering up the new orderId? or is there a way of merely offering up an
 'item' and then getting recommendations based merely on the item using the
 data already stored and the relationships with my item?

 My assumptions:
 #1
 I am assuming the data model is a static island of data that has been
 processed (flattened) overnight (most probably by an Hadoop process) due to
 the size of this data ... rather than a living document that is updated as
 soon as new data is available.
 #2
 I'm also assuming that instead of reading in the data model and
 providing recommendations 'on the fly' I will have to run thru every item
 in my catalogue and find out the top 5 recommended items that are ordered
 with each item (most probably via a Hadoop process) and then store this
 output in dynamoDb or luncene for quick access.

 Sorry for all the questions but it such an interesting subject.


 On 11 April 2013 22:04, Ted Dunning ted.dunn...@gmail.com wrote:

 Actually, making this user based is a really good thing because you get
 recommendations from one session to the next.  These may be much more
 valuable for cross-sell than things in the same order.


 On Thu, Apr 11, 2013 at 12:50 PM, Sean Owen sro...@gmail.com wrote:

 You can try treating your orders as the 'users'. Then just compute
 item-item similarities per usual.

 On Thu, Apr 11, 2013 at 7:59 PM, Billy b...@ntlworld.com wrote:
  Thanks for replying,
 
 
  I don't have users, well I do :-) but in this case it should not
 influence
  the recommendations
 
  ,
  these need to be based on the relationship between
  
  items ordered with other items
  in the 'same order'
  .
 
  E.g. If item #1 has been order with item #4
 
  [
  22
  ]
  times and item #1 has been order with item #9
  [
  57
  ]
  times then
  if I added item #1 to my order
  these would both be recommended
  but item #9 would be recommended above item #4 purely based on the fact
 that
  the relationship between item #1 and item #9 is greater than the
  relationship with item #4.
 
  What I don't want is; if a user ordered items #A, #B, #C separately
  'at some point in their order history' then recommen
  d #A and #C to other users who order #B ... I still don't want this if
 the
  items are similar and/or the users similar.
 
  Cheers
 
  Billy
 
 
 
  On 11 Apr 2013 18:28, Sean Owen sro...@gmail.com wrote:
 
  This sounds like just a most-similar-items problem. That's good news
  because that's simpler. The only question is how you want to compute
  item-item similarities. That could be based on user-item interactions.
  If you're on Hadoop, try the RowSimilarityJob (where you will need
  rows to be items, columns the users).
 
  On Thu, Apr 11, 2013 at 6:11 PM, Billy b...@ntlworld.com wrote:
   I am very new to Mahout and currently just ready up to chapter 5 of
   'MIA'
   but after reading about the various User centric and Item centric
   recommenders they all seem to still need a userId so still unsure if
   Mahout
   can help with a fairly common recommendation.
  
   My requirement is to produce 'n' item recommendations based on a
 chosen
   item.
  
   E.g. if I've added item #1 to my order then based on all the
   other items; in all the other orders for this site, what are the
   likely items that I may also want add to my order based; on the item
 to
   item relationship in the history of orders of this site?
  
   Most probably using the most popular relationship between the item I
   have
   chosen and all the items in all the other orders.
  
   My data is not 'user' specific; and I don't think it should be, but
 more
   like order specific as its the pattern of items in each order that
  

Re: Is Mahout the right tool to recommend cross sales?

2013-04-11 Thread Pat Ferrel
Do you not have a user ID? No matter (though if you do I'd use it) you can use 
the item ID as a surrogate for a user ID in the recommender. And there will be 
no filtering if you ask for recommender.mostSimilarItems(long itemID, int 
howMany), which has no user ID in the call and so will not filter. Since the 
recommender doesn't know you are using item IDs for user IDs this should work 
fine.

This allows you to use the in-memory version of the recommender as it is 
described in MiA. The Row and ItemSimilarityJobs are mapreduce and will produce 
results for all items in a batch. This is fine and will produce much the same 
results but you will have to code up the query part yourself as a 
runtime/live/service component. Using the in-memory recommender gives you a 
query interface to call whenever you are showing a page to the user.

Using the user ID will allow you to make and blend in user based 
recommendations, which are calculated based on individual user history. They 
may not be your primary recommendations, but when you dont have enough item 
similarities, you can fall back or blend in user recommendations.

On Apr 11, 2013, at 2:42 PM, Sean Owen sro...@gmail.com wrote:

You can actually create a user #6 for your new order. Or you can use
the anonymous user function of the library, although it's hacky.

We may be mixing up terms here. DataModel is a class that has
nothing to do with Hadoop. Hadoop in turn has no part in real-time
anything, like recommending to a brand-new user. However it could
build an offline model of item-item similarities and you could do
something like a most-similar-items computation for a given new basket
of goods. That is effectively what the anonymous user function is
doing anyway.

You can precompute all recommendations for all items but that's a lot
of work! It's easy to get away with it with a thousand items, but with
a million this may be infeasibly slow.

On Thu, Apr 11, 2013 at 10:38 PM, Billy b...@ntlworld.com wrote:
 As in the example data 'intro.csv' in the MIA it has users 1-5 so if I ask
 for recommendations for user 1 then this works but if I ask for
 recommendations for user 6 (a new user yet to be added to the data model)
 then I get no recommendations ... so if I substitute users for orders then
 again I will get no recommendations ... which I sort of understand so do I
 need to inject my 'new' active order; along with its attached item/s into
 the data model first and then ask for the recommendations for the order by
 offering up the new orderId? or is there a way of merely offering up an
 'item' and then getting recommendations based merely on the item using the
 data already stored and the relationships with my item?
 
 My assumptions:
 #1
 I am assuming the data model is a static island of data that has been
 processed (flattened) overnight (most probably by an Hadoop process) due to
 the size of this data ... rather than a living document that is updated as
 soon as new data is available.
 #2
 I'm also assuming that instead of reading in the data model and
 providing recommendations 'on the fly' I will have to run thru every item
 in my catalogue and find out the top 5 recommended items that are ordered
 with each item (most probably via a Hadoop process) and then store this
 output in dynamoDb or luncene for quick access.
 
 Sorry for all the questions but it such an interesting subject.
 
 
 On 11 April 2013 22:04, Ted Dunning ted.dunn...@gmail.com wrote:
 
 Actually, making this user based is a really good thing because you get
 recommendations from one session to the next.  These may be much more
 valuable for cross-sell than things in the same order.
 
 
 On Thu, Apr 11, 2013 at 12:50 PM, Sean Owen sro...@gmail.com wrote:
 
 You can try treating your orders as the 'users'. Then just compute
 item-item similarities per usual.
 
 On Thu, Apr 11, 2013 at 7:59 PM, Billy b...@ntlworld.com wrote:
 Thanks for replying,
 
 
 I don't have users, well I do :-) but in this case it should not
 influence
 the recommendations
 
 ,
 these need to be based on the relationship between
 
 items ordered with other items
 in the 'same order'
 .
 
 E.g. If item #1 has been order with item #4
 
 [
 22
 ]
 times and item #1 has been order with item #9
 [
 57
 ]
 times then
 if I added item #1 to my order
 these would both be recommended
 but item #9 would be recommended above item #4 purely based on the fact
 that
 the relationship between item #1 and item #9 is greater than the
 relationship with item #4.
 
 What I don't want is; if a user ordered items #A, #B, #C separately
 'at some point in their order history' then recommen
 d #A and #C to other users who order #B ... I still don't want this if
 the
 items are similar and/or the users similar.
 
 Cheers
 
 Billy
 
 
 
 On 11 Apr 2013 18:28, Sean Owen sro...@gmail.com wrote:
 
 This sounds like just a most-similar-items problem. That's good news
 because that's simpler. The only question is how you want to compute
 

Re: Is Mahout the right tool to recommend cross sales?

2013-04-11 Thread Sebastian Schelter
You can also use the new MultithreadedBatchItemSimilarities class to
efficiently precompute item similarities on a single machine without
having to go to MapReduce.

On 12.04.2013 00:54, Pat Ferrel wrote:
 Do you not have a user ID? No matter (though if you do I'd use it) you can 
 use the item ID as a surrogate for a user ID in the recommender. And there 
 will be no filtering if you ask for recommender.mostSimilarItems(long itemID, 
 int howMany), which has no user ID in the call and so will not filter. Since 
 the recommender doesn't know you are using item IDs for user IDs this should 
 work fine.
 
 This allows you to use the in-memory version of the recommender as it is 
 described in MiA. The Row and ItemSimilarityJobs are mapreduce and will 
 produce results for all items in a batch. This is fine and will produce much 
 the same results but you will have to code up the query part yourself as a 
 runtime/live/service component. Using the in-memory recommender gives you a 
 query interface to call whenever you are showing a page to the user.
 
 Using the user ID will allow you to make and blend in user based 
 recommendations, which are calculated based on individual user history. They 
 may not be your primary recommendations, but when you dont have enough item 
 similarities, you can fall back or blend in user recommendations.
 
 On Apr 11, 2013, at 2:42 PM, Sean Owen sro...@gmail.com wrote:
 
 You can actually create a user #6 for your new order. Or you can use
 the anonymous user function of the library, although it's hacky.
 
 We may be mixing up terms here. DataModel is a class that has
 nothing to do with Hadoop. Hadoop in turn has no part in real-time
 anything, like recommending to a brand-new user. However it could
 build an offline model of item-item similarities and you could do
 something like a most-similar-items computation for a given new basket
 of goods. That is effectively what the anonymous user function is
 doing anyway.
 
 You can precompute all recommendations for all items but that's a lot
 of work! It's easy to get away with it with a thousand items, but with
 a million this may be infeasibly slow.
 
 On Thu, Apr 11, 2013 at 10:38 PM, Billy b...@ntlworld.com wrote:
 As in the example data 'intro.csv' in the MIA it has users 1-5 so if I ask
 for recommendations for user 1 then this works but if I ask for
 recommendations for user 6 (a new user yet to be added to the data model)
 then I get no recommendations ... so if I substitute users for orders then
 again I will get no recommendations ... which I sort of understand so do I
 need to inject my 'new' active order; along with its attached item/s into
 the data model first and then ask for the recommendations for the order by
 offering up the new orderId? or is there a way of merely offering up an
 'item' and then getting recommendations based merely on the item using the
 data already stored and the relationships with my item?

 My assumptions:
 #1
 I am assuming the data model is a static island of data that has been
 processed (flattened) overnight (most probably by an Hadoop process) due to
 the size of this data ... rather than a living document that is updated as
 soon as new data is available.
 #2
 I'm also assuming that instead of reading in the data model and
 providing recommendations 'on the fly' I will have to run thru every item
 in my catalogue and find out the top 5 recommended items that are ordered
 with each item (most probably via a Hadoop process) and then store this
 output in dynamoDb or luncene for quick access.

 Sorry for all the questions but it such an interesting subject.


 On 11 April 2013 22:04, Ted Dunning ted.dunn...@gmail.com wrote:

 Actually, making this user based is a really good thing because you get
 recommendations from one session to the next.  These may be much more
 valuable for cross-sell than things in the same order.


 On Thu, Apr 11, 2013 at 12:50 PM, Sean Owen sro...@gmail.com wrote:

 You can try treating your orders as the 'users'. Then just compute
 item-item similarities per usual.

 On Thu, Apr 11, 2013 at 7:59 PM, Billy b...@ntlworld.com wrote:
 Thanks for replying,


 I don't have users, well I do :-) but in this case it should not
 influence
 the recommendations

 ,
 these need to be based on the relationship between
 
 items ordered with other items
 in the 'same order'
 .

 E.g. If item #1 has been order with item #4

 [
 22
 ]
 times and item #1 has been order with item #9
 [
 57
 ]
 times then
 if I added item #1 to my order
 these would both be recommended
 but item #9 would be recommended above item #4 purely based on the fact
 that
 the relationship between item #1 and item #9 is greater than the
 relationship with item #4.

 What I don't want is; if a user ordered items #A, #B, #C separately
 'at some point in their order history' then recommen
 d #A and #C to other users who order #B ... I still don't want this if
 the
 items are similar and/or the users