Collective or professional opinions are defined as meeting a higher standard to substantiate the opinion.
In economics, other social sciences and philosophy, analysis based on opinion is referred to as normative analysis (what ought to be), as opposed to positive analysis, which is based on scientific observation (what materially is or is experimentally demonstrable).
Historically, the distinction of demonstrated knowledge and opinion was articulated by Ancient Greek philosophers. Today Plato's analogy of the divided line is a well-known illustration of the distinction between knowledge and opinion, or knowledge and belief, in customary terminology of contemporary philosophy. Opinions can be persuasive, but only the assertions they are based on can be said to be true or false.
Collective and professional opinions
The public opinion is the aggregate of individual attitudes or beliefs held by the population. Public opinion can also be defined as the complex collection of opinions of many different people and the sum of all their views.
A "scientific opinion" is any opinion formed via the scientific method, and so is necessarily evidence-backed. A scientific opinion which represents the formally-agreed consensus of a scientific body or establishment, often takes the form of a published position paper citing the research producing the scientific evidence upon which the opinion is based. "The scientific opinion" (or scientific consensus) can be compared to "the public opinion" and generally refers to the collection of the opinions of many different scientific organizations and entities and individual scientists in the relevant field.
A "legal opinion" or "closing opinion" is a type of professional opinion, usually contained in a formal legal-opinion letter, given by an attorney to a client or a third party. Most legal opinions are given in connection with business transactions. The opinion expresses the attorney's professional judgment regarding the legal matters addressed. A legal opinion is not a guarantee that a court will reach any particular result. However, a mistaken or incomplete legal opinion may be grounds for a professional malpractice claim against the attorney, pursuant to which the attorney may be required to pay the claimant damages incurred as a result of relying on the faulty opinion.
A "judicial opinion" or "opinion of the court" is an opinion of a judge or group of judges that accompanies and explains an order or ruling in a controversy before the court, laying out the rationale and legal principles the court relied on in reaching its decision. Judges in the United States are usually required to provide a well-reasoned basis for their decisions and the contents of their judicial opinions may contain the grounds for appealing and reversing of their decision by a higher court.
An "editorial opinion" is the stated opinion of a newspaper or of its publisher, as conveyed on the editorial page.