1. Setting up the working environment

2. Import data

3. Sample structure understanding

3.1 Categorical variables

Majority of respondents are female in their 20s (20-24 yo), obtained University degree, having full-time jobs and originally from the South.

3.1.1 Sample structure table summary

Variable Level No. of respondents % Respondents
Age range 20-24 yo 173 57.67
Age range Above 35 yo 71 23.67
Age range 25-35 yo 56 18.67
Education level University 267 89.00
Education level High school 31 10.33
Education level Below high school 2 0.67
Gender Female 199 66.33
Gender Male 101 33.67
Job Full-time 155 51.67
Job Student 103 34.33
Job Part-time 33 11.00
Job Housework 9 3.00
Native village South 195 65.00
Native village Central 66 22.00
Native village North 39 13.00

3.1.2 Sample structure plot

3.2 Continuous variables

Respondent age is not normally distributed. 1/3 respondents are 22 years old.

3.3 Continuous vs. categorical variables

Female respondents age is extremely right skewed.

Age distributions of those who are from the South and Central are wider spread than the North group.

4. Data cleaning

Coding error is spotted! Each variable in brand section should have two levels only. Khai hoan brand has 4 levels.

      ID                phu.quoc        phan.thiet     nam.ngu   
 Length:300         kh.pq   :256   kh.pt     :282   kh.nn  :150  
 Class :character   phu.quoc: 44   phan.thiet: 18   nam.ngu:150  
 Mode  :character                                                
                                                                 
     hanh.phuc        thanh.phong      de.nhi       chinsu       co.hau   
 hanh.phuc: 19   kh.tp      :299   de.nhi : 25   chinsu: 56   co.hau:  1  
 kh.hp    :281   thanh.phong:  1   kh.dnhi:275   kh.cs :244   kh.ch :299  
                                                                          
                                                                          
      hung.thinh     ba.mien        cholimex       nha.trang  
 hung.thinh: 39   ba.mien:  2   cholimex:  3   kh.nt    :292  
 kh.ht     :261   kh.bm  :298   kh.cho  :297   nha.trang:  8  
                                                              
                                                              
      hong.thanh      khai.hoan        thien.huong      tu.tuyet  
 hong.thanh:  4   k        :  7   kh.th      :298   kh.tt   :298  
 kh.hthanh :296   kh.kh    :259   thien.huong:  2   tu.tuyet:  2  
                  khai.hoan:  5                                   
                  NA's     : 29                                   
      lien.thanh 
 kh.lt     :283  
 lien.thanh: 17

Nam Ngu is the most popular brand and almost triple the second player - Chinsu in terms of the number of responses.

There are few respondents gave more than the required number of responses (maximum is 2).
Respondent ID Brand 1 Brand 2 Brand 3 Brand 4 Number of brands declared
KS2_29 phu.quoc phan.thiet nam.ngu hung.thinh 4
KS2_111 phu.quoc nam.ngu nha.trang NA 3
KS2_130 nam.ngu chinsu cholimex NA 3
KS2_181 hanh.phuc chinsu hung.thinh NA 3
KS2_224 phu.quoc nam.ngu lien.thanh NA 3
KS2_255 hung.thinh tu.tuyet lien.thanh NA 3
KS2_109 phu.quoc hung.thinh NA NA 2
KS2_110 hung.thinh cholimex NA NA 2
KS2_113 de.nhi hung.thinh NA NA 2
KS2_115 nam.ngu de.nhi NA NA 2

5. Data exploration

5.1 Key influencing factors

Average rating score of 6 key factors:
Health Sensory Tradition Quality Price Convenience
3.95 4.09 3.98 4.16 4 4.08

Quality seems to be the most influencing factor.

The challenge of visualing ordinal categorical variables:

Using ‘jitter’ trick…

… or using dimension reduction technique?

Revealing special cases:

Respondent 19:
Health Sensory Tradition Quality Price Convenience
1 2 2 3 4 4
Respondent 133:
Health Sensory Tradition Quality Price Convenience
5 5 5 5 1 1

5.2 Important factors

Looking into sub-factors, the product origin seems to be the most concerning factor when choosing fish sauce products.
Factors Value
Convenience
Can be bought in shops close to where I live or work 3.85
Is easily available in shops and supermarkets 4.04
Is easy to prepare 3.83
Takes no time to prepare 3.91
Health
Contains lots of protein, vitamins, omega-3, iron and lysine 3.9
Eating with fish sauce will help us eat more, thus providing more active energy 3.68
Keeps me healthy 3.82
Price
Is cheap 3.25
Is good value for money 4.02
Is not expensive 3.65
Quality and safety
Conform to Vietnam or global quality standard 3.8
Get certification of Vietnam high quality goods by consumers 3.8
Has a clear origin of production 4.18
Has Eco-friendly packaging 3.57
Sensory appeal
Distinctive brownish color 3.7
Eye-catching packaging 3.58
Has a pleasant texture 3.7
Smells nice 3.91
Tastes good 4.03
Traditional value
Be processed/prepared in a special way 3.9
Has origin of materials (geographical indications) 4.23
Is associated to specific celebrations of my country/family 3.55
Is familiar with me and my family 3.74
Is special product that reflects the nation or local culture 4.06

The origin factor is highly important for both male and female groups. Male respondents seem to give higher scores in most of the factors compared to their counterparts. However, female respondents seem to care more about whether the products are available in shops, keeping them healthy and reflecting the local culture than male.

Factors Male Female
Convenience
Can be bought in shops close to where I live or work 3.89 3.83
Is easily available in shops and supermarkets 3.99 4.07
Is easy to prepare 3.84 3.82
Takes no time to prepare 3.94 3.9
Health
Contains lots of protein, vitamins, omega-3, iron and lysine 4.06 3.82
Eating with fish sauce will help us eat more, thus providing more active energy 3.74 3.65
Keeps me healthy 3.76 3.85
Price
Is cheap 3.18 3.28
Is good value for money 4.05 4.01
Is not expensive 3.66 3.64
Quality and safety
Conform to Vietnam or global quality standard 3.9 3.74
Get certification of Vietnam high quality goods by consumers 3.9 3.75
Has a clear origin of production 4.2 4.17
Has Eco-friendly packaging 3.58 3.56
Sensory appeal
Distinctive brownish color 3.66 3.71
Eye-catching packaging 3.65 3.55
Has a pleasant texture 3.76 3.67
Smells nice 4.03 3.85
Tastes good 4.12 3.98
Traditional value
Be processed/prepared in a special way 3.91 3.89
Has origin of materials (geographical indications) 4.24 4.23
Is associated to specific celebrations of my country/family 3.53 3.56
Is familiar with me and my family 3.71 3.75
Is special product that reflects the nation or local culture 3.99 4.09