Structured: Questionnaire that contains only closed-ended questions

Semi-structured: Contains both open-ended and closed ended questions

Unstructured: Contains open-ended questions exclusively or majority

I can tell you what I understand a semi-structured interview to be. It will have a list of topics to cover, and a list of discussion prompts associated with each topic area. A structured interview will simply consist of reading out the questions you have decided upon, and recording qualitative (narrative) responses. Does this help? I'm not sure about semi-structured questionnaires - I associate questionnaires with quantitative data collection - multiple choice and yes or no type data so they can't be unstructured! 

My own understanding is thus: A structured questionnaire is rigid with responses which you tick off such as yes or no, or select from a list of options. Responses are limited only to what is on the questionnaire. In semi-structured, there are set questions, but responses from participants are qualitative and may vary but every one gets asked the same questions. An unstructured questionnaire asks usually general open ended or questions that are answered in different ways by respondents, such questions as you may use in focus group discussions or motivational interviewing. I hope this helps

Zewdneh, the main purpose of those different types of interview questions is to avoid biasdness and to control the qualitative answers of the respondents. Therefore, the more the questionnaire is structured, the more we are leading the respondent into our own way. Also there is high possibility that you may miss so many important points that the respondents can provide you.

Structured: Questionnaire that contains only closed-ended questions

Semi-structured: Contains both open-ended and closed ended questions

Unstructured: Contains open-ended questions exclusively or majority

I think the definition of structured questionnaire has already been clarified. For the semi-structured and unstructured questionnaires the points of view and their use vary. To me I consider an unstructured questionnaire more like a list of generic topics with some probes to be covered during a discussion either one to one or group where the interviewer or rather facilitator can use their own framed questions to make sure the respondent understand what is being discussed and ensure enough information has been obtained. The semi-structured questionnaires include are a combination of both structured and un-structured segments within the same questionnaire often designed in a way where a close ended (either yes/no or multiple choice question) is followed by a very open probe for further explanation about why the respondent selected a given response to the preceding question. I hope this helps. 

As to my understanding, structured questionnaire consists of items or questions with totally pre-categorized response options. So, as someone has already said it is a rigid type. It can be yes/no, or multiple-choice, or Likert scale, or other rating scale format in nature. The semi-structured questionnaire has items with some pre-categorized response options and additional open-ended options. Thus, it is also known as partially categorized questionnaire. The unstructured one is the one with a totally open-ended questions and it gives more freedom for the respondents to give responses in the way and to the extent and depth they like.

Semi-structured questionnaire has open questions , allowing new ideas to be brought up during the interview as a result of what the interviewee says. The aim of this type to explore more unknown thoughts and ideas from the interviewee While a structured questionnaire or interview has a rigorous set of questions which does not allow one to divert, usually set of questions with definite known answers like yes/no, or agree/disagree for example.

I think you have got enough right answers about the type of questionnaries. But It is important to highlight that when you design a questionnarie you have to bear in mind what you want to do and how you want to analyse the information. If you use a structured questionnarie is easier to use quantitative tools of analysis than if you use a unstructured questionnaire. But at the same time if you use the unstructured one you will be able to have different points of view although you will have to analyse them only from a descriptive and qualitative point of view.

So, I mean that the design of the questionnaire will define your next steps too, so you have to be careful with it and think about it from a global perspective, not forgetting the analysis of the results obtained from the questionnaire.

Structured

Each question is specifically constructed and asked in the same words through all the respondents

Questions are well constructed before data collection exercise

Semi-structured

Though structured; there is the opportunity to probe for details during questions administration

Questions can be restructured to suit the interviewee and pursue unexpected trend of thoughts

Questions are not necessarily in a fixed order

Unstructured

Highly informal conversation with no systematic format to follow

No predetermined set of questions but trends and patterns are identified in the field of research

It depends on what the researcher is seeking to accomplish. If they are looking to gather evidence, they will lead the respondent using a structured interview. Semi-structured interview gives way for probing in particular areas of interest displayed during the process, opening the gateway of discovery that structured interviews do not allow. In the unstructured, a free flow of valuable information can be obtained where emerging patterns, themes and nuances can be found. 

All great answers. I advise that you seriously take note of the fact that in order to avoid biases and to allow respondents give you information that is detailed, you don`t limit them with close ended structured questionnaires. The choice is always yours depending on whether you go qualitative and or quantitative.

Cheers

I agree Amandus, to gain full understanding of actions by the respondent one must allow the question to probe and divulge information that would otherwise be forfeited with structured questioning.

Great answers, to add YES/NO (structured) responses on a questionnaire are not always the strongest for quantitative data analysis

I agree ingenerally Rajasekharan Pillai Answer.

Structured Interview. This is also known as a formal interview .The questions are asked in a set / standardized order and the interviewer will not deviate from the interview schedule or probe beyond the answers received (so they are not flexible).These are based on structured, closed-ended questions.

 Unstructured Interview (discovery interviews) .An interview schedule might not be used, and even if one is used, they will contain open-ended questions that can be asked in any order. Some questions might be added / missed as the Interview progresses  example : 'Can you tell me about your experience of visiting the dentist?'

 Semi-structured interviews consist of several key questions that help to define the areas to be explored, but also allows the interviewer or interviewee to diverge in order to pursue an idea or response in more detail

Hello, Zewdneh, to respond to your question, my understanding is that most methodologists let us know that a survey, is commonly  a strategy for the Quantitative research, where researchers try understanding the relationship between variables as well as describe, attitudes, opinions etc using large samples.  Therefore, a structured-questionnaire is often used but can have some open-ended questions, usually for the purposes of post coding. On the other hand, semi-structured and unstructured questions endear more to interviews and I could not agree more with the explanations given by others about what they are or mean.   

A structured questionnaire is restrictive. It gives no room for a respondent to express himself beyond what the researcher has set out to know.

I agree with all the previous answers. Only to say that to choose between these different kinds of questionnaire you have to bear in mind what analysis you want to do with the information obtained from the questionnaire.

I agree with explanations given in relation to the basic differences. But on the other leg of the question, I understand that structured a questionnaire is mostly used in surveys. Unstructured and semi-structured go with interviews as often as not. 

I agree with all the above explanations.  Just to add few points: structured questionnaire has a fixed alternatives like multiple choice , yes/no or true/false questions and mostly used for quantitative studies.  Unstructured questionnaire is open ended questions and  the respondents are not restricted to a fixed choice. This is usually used in qualitative studies to explore the  opinion of the interviewees. It could be applied during  in-depth interview and focus group discussion (FGD). Semi-structured questionnaire is in between of the two,  which is  fixed to some extent but  there is a room for the interviewees to give additional answer or explanations for the question. 

Additionally, Structured interviews are fairly quick to conduct which means that many interviews can take place within a short amount of time. 

structured questionnaire are designed in such a way that the interviewee is restricted to the already designed set of questions without given room to express his/her self. however, structured questionnaires are always easier to analyse

I don't know, most responses here talked about "questionnaire" initially and end up mentioning "interviews" to buttress their points. Is there no difference between "unstructured questionnaire" and "interview"?

Styles of interviewing techniques include the formal structured approach and the more flexible semi-structured form. The nature of the research being conducted helps determine the most appropriate type of interviews to conduct.

Structured interviews require the use of a set of standardized questions that the researcher creates in advance. Often, there are few open-ended questions in the interview guide, according to the qualitative research guidelines project at the Robert Wood Johnson Foundation in New Jersey. In this way, structured interviews resemble questionnaires or surveys. Semi-structured interviews also use an interview guide with some questions developed in advance but also allow the interviewer to stray from the interview guide, asking follow-ups as the interviewer believes appropriate. For example, an interviewee's responses to a prepared question may raise issues that the interviewer wishes to explore further follow-up queries.

Structured interviews keep the order and phrasing of the questions consistent across interviews to ensure consistency in the data being collected, the Robert Wood Johnson Foundation reported. In contrast, semi-structured interviews may prescribe a combination of questions and more general topics to cover. Questions in semi-structured interviews are more open-ended to allow interviewers to follow issues that diverge from the guide. Because of the open-ended responses, interviewers will often tape-record semi-structured interviews.

Researchers use structured interviews when they have a well-developed understanding of the topic being studied. When sufficient research literature exists to provide sufficient knowledge to develop relevant questions, a structured interview is sufficient, the Robert Wood Johnson Foundation reported. When the literature is less developed and the researcher wants to develop a better understanding of the topic under consideration, semi-structured interviews provide a way to gain additional knowledge by allowing respondents to express their views in their own words.

This means that structured interviews make it easier to code the data for analysis. Semi-structured interviews reveal more open-ended qualitative data that require more time to analyze because the interviewer must read through notes and listen to transcripts, noting and summarizing important points and patterns.

I agree with Pillai's answer.

Structured: Questionnaire that contains only closed-ended questions

Semi-structured: Contains both open-ended and closed ended questions

Unstructured: Contains open-ended questions exclusively or majority

Structured interviews are such that the interviewer comes prepared with a list of questions he wants to ask and the respondent simply answers what he/she is asked. They are useful for researches that can easily be coded and in most cases, the codes are already on ground. You basically just fit the responses in. They are close-ended

For semi-structured, the questions are open ended and the respondent is allowed to talk/respond in details. You come into the interview with an interview guide which may change as you proceed. For instance, the respondent may say something you have not considered but you now find useful. You can include this new ideas in your next interview. They are particularly helpful with inductive methodologies such as grounded theories.

The way I view unstructured interviews is 'listening to a gist'. You simply listen to the respondent talk about his/her experience. It is more story telling and you pick what you want from the story, hence the name 'unstructured'. You are however allowed to seek clarifications. The best way to this form of interview is to build some trust and 'closeness' with your respondent. Apparently, such approach will be useful in phenomenological studies.

Finally, the unstructured and semi-structured interviews allow respondents to express themselves freely and can be rewarding, even though time consuming.

I hope this helps.

i agreed with Olalalakine's statements. I he explained in detailed the types. I have six years work experience with WWF-Pakistan, where we frequently used different types of questionnaires to asses a problem or get data depending upon the population size and demographic conditions of the target locality.

IT is a matter of open-endedness, close questions and a mixed one.

my questions are open-ended

This is an important question in research methodology. However, there are some research scientists who argue that, what is or can be structured is NOT a questionnaire BUT rather questions. For instance, most or nearly all of the responses provided above are with reference to structured, semi-structured or unstructured "questions". What are your comments about this?

The important point is whether your sample represents the population you are targeting. In a structured survey this is more difficult as the respondents play in the field which you define with your questions and answer selections. In a semi-structured interview you have guiding questions but the interview develops in a direction influenced by the respondent. Usually after a number of interviews you should start getting the same results which means that you managed to capture the population with your sample size of respondents.

I share Olalekan Olaluwoye's statements.

In a structured questionnaire only closed-ended questions are used, in a semi-structured questionnaire both open-ended and closed ended questions are used while in a unstructured questionnaire, only open-ended questions are used related to the context. Structured questions are used for quantitative research on a larger sample while unstructured question are used in qualitative research on a small sample.

I too agree with suhail's answer, one thing in semi structured questionnaire, in a single question, you can have closed ended and open ended for example do you like coffee: yes/No, if yes pl explain why? example for unstructured, interviewing a popular personality in television like how do you choose this field? What impress you to choose this field? etc

I agree with Mr. Olalekhan and Mr. Pillai. Structured questionnaire may be converted an instrument with standard testing criteria like content validity.

According to my understanding of the said topic:

1. Structured Questionnaire has a specific structure that encompasses the items (questions) for each construct (variable). We call it structured because we segments with headings that defines our target variable for which we ask questions specifically under that segment and heading. Questions are commonly closed ended and scalable.

2. Semi structured questionnaire also consists of variables but questions for those variables are spread all over the form, some questions work for more than one variable which is why we cannot put headings and divide questionnaire into segments. Questions are closed ended but open ended questions can be added to accomplish certain goals.

3. Unstructured questionnaire is commonly used for data mining companies where neither the respondent nor the researcher can identify items for each variable, as the spread is vast and covers more variable generally. Contains Ordinal and scalable closed ended questions as well as open ended qualitative in nature questions are also introduced. This kids of questionnaire serves a broad spectrum of researches.

I hope this helps!

thanks a lot but I hope if there are more examples

thanks