Generally speaking, naturalism makes claims about the 'true' or ontological nature of things, persons, social practices etc., about 'how they really are', while positivism abstains from statements about any essence, merely noticing what is observable.

In this sense, naturalism is very (some would say: overly) normativistic, while positivism purports to be (some would say: untruly) neutral.  

Naturalism is one of those terms that has many senses. However, if one thinks of naturalism broadly as the attempt to explain the world in the manner of the natural sciences, i.e. without invoking anything supernatural, spiritual, or intentional, then one can distinguish various naturalist positions in terms of their ontological commitments. So construed, positivism (i.e. logical positivism or logical empiricism) can be regarded as a species of naturalism having the fewest ontological commitments (i.e. just the observations).

Could you give examples, i. e. concrete debates, that receive either one of these labels? You are asking for the difference between certain kinds of  studies. I'm not sure, what you are referring to. If you are referring to certain debates in the philosophy of science (in which the labels `naturalism' and `positivism' are used), then these labels may be used to cover a wide variety of loosely related views. Since every participant is free to use these terms in the way they choose, it is hard to give a general answer. If you have a narrower sense in mind, please specify it.

I do not disagree with the answers given by Ulf Bohmann and Karl Pfeifer, I'm afraid that I'm unable to attempt to give a better answer or evaluate the answers given because there is not enough context for me to do so.

Mainz, Germany

Dear Tapia & readers,

Positivism is, or is closely tied up with, a philosophical doctrine concerning linguistic or cognitive meaning. Paradigmatically, the idea is that the meaning of a declarative statement  or sentence (aside from those of logic or mathematics) is its method of verification; and whatever has no clear method of verification is, according to this kind of doctrine, literally meaningless. Part of the motivation of the doctrine was to escape the metaphysical debates of the later nineteenth and early twentieth century--those connected with absolute idealism in particular.

While there are various refinements and alternative versions of the verificationist conception of meaning, once verificationism was rejected, positivism generally lost influence. Surely, statements can be meaningful although we do not presently know how to verify or refute them, though that situation does, of course, present problems. Positivism is historically connected with the writings of Ernst Mach and with the philosophers of the Vienna circle.

Naturalism is a philosophy which appeals to the idea of nature and states that answers to our problems and question can be given in terms of natural phenomena, such as those we find in the natural sciences. While it can be given a metaphysical interpretation and sometimes has been so interpreted, it need be no more metaphysical than the theories of the sciences. "Naturalistic metaphysics" is not merely redundant, but it has often been contested by advocates of naturalism. 

Naturalism aims to be inclusive of the scholarly disciplines and social sciences as well as the natural sciences. So, it is a general philosophical outlook; but it need not be dogmatic --though some versions have been dogmatic. In consequence, methodological naturalism looks for naturalistic answers without prohibiting the possibility of non-naturalistic approaches. Naturalism is not to be identified with materialism, since it allows that the sorts of things we must assume or postulate in answering our problems and questions will form an open class of sorts or kinds of things. As a rule, naturalism is anti-dualistic and also opposes monism. 

H.G. Callaway

Dear Aaron. All the answers offered so far seems to me to be correct answers, but each is answering to a different sense that the term 'naturalistic' can take (just as Karl Pfeifer points out). I can identify one more. In qualitative research one comes across the terms 'naturalistic inductive inquiry'. Here the idea is that 'naturalistic' is to study some or other phenomenon close to its natural habitat (as opposed to in an 'unnatural' laboratory setting). To say that it is 'inductive' is to say that it is research done without guidance of hypothesis or theory (the hypotheses are then inductively inferred from the observations). I think it is strange to apply the term 'naturalistic' to qualitative research because most such studies are based on interviews, and interviews are not a natural setting. At best observational studies could be naturalistic in this sense, i.e. when you try to become a part of a milieu and observe it from within so to speak. Finally, to combine 'naturalistic' and 'inductive' in this sense is really to combine 'naturalistic' and 'positivist' in one. In the end I think Sven Beecjen is right that you won't get a good answer until you say which contexts in particular you are talking about

Mainz, Germany

Dear all,

Note the definition of "positivism" from Webster's:

Definition of positivism

1a :  a theory that theology and metaphysics are earlier imperfect modes of knowledge and that positive knowledge is based on natural phenomena and their properties and relations as verified by the empirical sciences b :  logical positivism

Definition of logical positivism

:  a 20th century philosophical movement holding that all meaningful statements are either analytic or conclusively verifiable or at least confirmable by observation and experiment and that metaphysical theories are therefore strictly meaningless —called also logical empiricism

---End quotation

These definitions appear to reflect more general usage as well as that specific to the history of philosophy.

Compare Webster's definition of "naturalism":

Definition of naturalism

1 :  action, inclination, or thought based only on natural desires and instincts

2 :  a theory denying that an event or object has a supernatural significance; specifically :  the doctrine that scientific laws are adequate to account for all phenomena.

---End quotation

The first entry reflects more general usage. The second entry seems to reflect specifically, dogmatic forms of naturalism--anti-super-naturalism. This is, no doubt an influential version. But what if someone says, e.g., that some things happen by law and other things by accident, chance or coincidence (as Aristotle does). Could this be an alternative form of naturalism?

It appears that the specific developments and alternatives of the tradition of philosophical naturalism are not well reflected in Webster's general purpose dictionary.

W.L. Reese, Dictionary of Philosophy and Religion, an older but useful American reference work, states that naturalism was an American development of the first half of the 20th century. It lists George Santayana, John Dewey, Morris Cohen, Ernest Nagel. Horace Kallen and Sidney Hook as representatives of this development. It mentions the refusal to equate naturalism with materialism (though Santayana did regard himself as a materialist) and notes that Dewey called his view "empirical naturalism."  Dewey, by the way, famously gave up the term "metaphysics."

H.G. Callaway

Please let me know if this reference/site is helpful to you:

Comparing positivist ( or objectivist) and naturalist (or interpretivist

...

http://www.unm.edu/~devalenz/505/compare.docNaturalist.

The purpose of research is to discover the truth. Realities are multiple, constructed, and holistic. The purpose is to understand meaning from the ...

Dennis

Dennis Mazur

Mainz, Germany

Dear Mazur,

You may want to check your reference. The link appears no be broken.

H.G. Callaway

Dear Mazur:

I could not open the link, sorry

ke wenyong

Mainz, Germany

Dear all,

This is perhaps the link intended above:

http://www.unm.edu/~devalenz/505/compare.doc

Have a look.

H.G. Callaway

Dear colleagues

Thank you very much for your valuable contributions.

With your comments I learned much more, I invite you to see the movie "Casas de Fuego", about the history of Chagas in Argentina, I was recommended to better understand the difference between naturalism and positivism.

You're very kind.

https://www.youtube.com/watch?v=o9hg_XYtie4

Mainz, Germany

Dear Tapia & readers,

From a Wikipedia stub,

Casas de fuego

From Wikipedia, the free encyclopedia

Casas de fuego is a 1995 Argentine biographical-drama historical film directed by Juan Bautista Stagnaro and starring Miguel Ángel Solá, Pastora Vega y Carola Reyna. It was released on August 31, 1995, and won seven awards, among them the "Kikito de Oro" for Best Film at the Gramado Film Festival and the Silver Condor Award for Best Film.

The film follows the life of Salvador Mazza, the Argentine physician who began investigating the Chagas disease in 1926 and over the years became the principal researcher in the country.[1] Mazza produced the first scientific confirmation of the existence of Trypanosoma cruzi in Argentina in 1927, eventually leading to support from local and European medical schools and Argentine government policy makers.[2] In Argentina and other countries the disease is known as mal de Chagas-Mazza (Chagas-Mazza disease).

---End quotation

H.G. Callaway

hi?

it is a general philosophical outlook; but it need not be dogmatic --though some versions have been dogmatic. In consequence, methodological naturalism looks for naturalistic answers without prohibiting the possibility of non-naturalistic approaches. Naturalism is not to be identified with materialism, since it allows that the sorts of things we must assume or postulate in answering our problems and questions will form an open class of sorts or kinds of things. As a rule, naturalism is anti-dualistic and also opposes monism.

Hi

Dear Maysam Toghraee

Thank you very much for your valuable contribution, I learn a lot from your knowledge