Types of References

The spouse has suggested that I attempt to explain the different type of references that are used by GMO and anti-GMO articles, and the scientific merit/trustworthiness of each.

Abstract or talk from a conference: as demonstrated by the Iranian president, you can organize a conference about anything you want. You can also invite guest speakers, who can talk about anything they'd like. Other talks are selected from the list of abstracts that are submitted from attendees. Submitting an abstract is a great opportunity to build a name for yourself and to share your findings. However, those findings are not vetted nor are they peer reviewed. Consequently, you could talk or share information from a study that subsequently does not get published. So unless a reference to an abstract or talk is paired with the data, it isn't very useful or verifiable

Opinion piece or editorial: opinions or editorials are found, not only in newspapers, but also in scientific journals. It is one of my pet-peaves to reference an editorial from a journal without clarification, because the bibliographical note looks very similar to a journal article. Luckily, opinions and editorials can be quickly identified by looking it up in pubmed, even if you don't have access/paid-subscription to the journal itself.

Comments: it's like writing an open letter. Anyone can write a comment to an organization or to a journal

News articles: this one's tricky. It all depends on the information in the news article. Too often, I read news articles where someone's opinion is shared and twisted into fact. For example: "5 people were injured in a car accident." That's a fact. "5 people were injured in a car accident: victim states that one of the drivers was speeding." Part fact, part opinion, and the opinion is from a person who isn't an expert in traffic accidents. There'd be more merit if it came from a police officer.

Journal article: these are supposed to be peer reviewed and vetted. The quality of the article often depends on the caliber of the journal (note the use of the term "often"), but duds and crummy findings do find their way into the best of journals (the infamous and discredited autism vaccine paper in Lancet is the first one that comes to mind). Some journal articles are reviews, where they don't publish any new findings, but present either a story or summary from a field of research.