An opinion without a purpose statement or thesis

[Anna232]

These statements are used at the end of the introduction before the first paragraph. The opinion is expressed in each but the purpose isn't mentioned. Is it correct to just express your opinion without mentioning what the essay is going to be about? They are followed by the first paragraph.
(Source: Taken from last year's exams. Regarding the structure of the essays, I followed one of the teacher's advice on this forum and asked about it here where I need to take the exam. As I found out the structure is very general. Introduction, paragraph 1 and 2 and conclusion. The samples are all very different which makes things even more confusing.

1. I strongly believe that the internet is the best and helpful way to communicate with others. (Lacks purpose statement)

2. I hold the view that the internet can have a positive impact on people's lives. This essay outlines the reasons behind my position.

3. It is my view that the internet has both a positive and a negative impact and this essay will present several arguments to support my viewpoint.
4. In my view the internet is quite beneficial in terms of getting knowledge. (Lacks purpose statement)

 

[Tarheel]

These statements are used at the end of the introduction before the first paragraph. The opinion is expressed in each but the purpose isn't mentioned. Is it correct to just express your opinion without mentioning what the essay is going to be about? They are followed by the first paragraph.
(Source: Taken from last year's exams. Regarding the structure of the essays, I followed one of the teacher's advice on this forum and asked about it here where I need to take the exam. As I found out the structure is very general. Introduction, paragraph 1 and 2 and conclusion. The samples are all very different which makes things even more confusing.

1. I strongly believe that the internet is the best and MOST helpful way to communicate with others. (Lacks purpose statement)

2. I hold the view that the internet can have a positive impact on people's lives. This essay outlines the reasons behind my position.

3. It is my view that the internet has both a positive and a negative impact and this essay will present several arguments to support my viewpoint.
4. In my view the internet is quite beneficial in terms of getting knowledge. (Lacks purpose statement)

Hm. I'm a little bit confused myself, but I'm sure that @emsr2d2 or @jutfrank can help you.