You need to separate different products of the brand then examine consumer's attitude towards them.

You should consider separating different products of the brand due to the differrences in market segmentation

 you need to consider  the time and the research method you are going to use. For example, if you are examining the consumer's attitude about apple products ( laptop, iphone , ipad and their watches ) then you need to ask the  respondents to rate their  product preference in  Apple. If not you can  concentrate on features of a particular product in that brand.( Features of Apple's Laptop and then carry on)

Thank you for your contribution to my query. Let me add something to consider. What would you suggest if I had a total amount of brands in which there is a certain brand name let say it is Brand A. This Brand has several kinds of products i.e. smart phone, laptop, tablet. Should I consider the different kinds of products as different brands and examine the consumer attitude towards them or should I take them as the same brand? Bear in mind that I have other brand names to examine too.

so if you are examining the brand preference, I will give you an example, If you are  examining the consumer's attitude  about  apple .Samsung, Lenovo and  Htc all of them has (smart phone,laptop and tablets)  .Then you should   examine  the  consumption pattern and brand preference of  electronic goods  with reference to the particular city or place.  In that case, you can ask them to rate their  consumer's attitude and brand  preference for Laptops( what is their favourite brand about apples laptop , lenovos laptop, etc( this is like out of the heterogeneous brands you are creating a homogeneous groups )

What if I ask them to say what they prefer instead of giving them the brands? How should I consider the answers? Just examining their attitude towards a major brand like Apple no matter what kind of products they have bought from Apple or examining their attitude separately for iphone or macbook or any other product of Apple?

 you need to examine the consumers' attitude for  each product separately such as phones as one product category and what is the brand they prefer when it comes to phones only. what is the consumer's opinion about  their brand preference in terms of 

laptops i.e what product they purchased and what is the brand they have purchased and why they have purchased .you can also consider   pre-purchase and post-purchase evaluation and whether they will recommend the particular brand for the particular products.  

Thank you very much for your contribution to my question

Since you are planning to study brand preference, most studies in this area posit that a BRAND  is more than a product. It is TRUST. The Brand Equity framework and the Brand Pyramid model too say that all the facets of a brand should be studies. Brand extensions in different product lines (For Apple) do leverage the value of a brand.. For customers, brands can simplify choice, promise a particular quality level, reduce risk, and/or engender trust. Brands are built on the product itself, the accompanying marketing activity, and the use (or non-use) by customers as well as others.

Brands thus reflect the complete experience that customers have with products. In a study you can always first seek to identify 'What does a particular brand' mean to them. Then adopt a attribute-based approach to arrive at a brand-product configuration. The tool of Multi-Dimensional scaling (MDS) can be used to explore some insights.. Which attribute associations are most stable and beneficial in the long run?

you should separate different products of the same brand 

Hi, Anastasios!

Interesting question! To me, it looks like the answer to your question depends on what you are trying to do here. For example, if you are studying the matter purely at a brand level, that is, comparing between say, Pepsi and Coke, I would ask questions related strictly at the brand level. That means I would be interested to find out overall issues like brand recall, brand salience, without wondering what’s happening at a product level. I could have consumed say a mineral water product of brand A and a cold drink of brand B, but at this time I am only interested in what the overall brand means to me.

 This matter becomes a whole lot different if you are trying to understand brand perceptions at a product-brand level. That is, for say automatic washing machines, which brands do I prefer and why? Here we’re studying about the brand at the product family level.

 Taking a particular strategy should be tied on with your research question. Else, you might find confounds getting into your design.

 So, you might want to clarify your research question for one to give a clearer suggestion to what would be a right approach here.

All the best with your research!

Hi,

I would say that its the brand as a whole which brings the effect collectively than just a product line. I would suggest to to catagorise the sample on the basis of product line and then a general view on the basis of common factors related to strategy and mar-com.

I brand is a brand whether it is a product or of multiple products.

Hope this helps