Observation Flashcards
Registration
subject S registers concrete entity x iff an image of x forms on the retina of the eyes of S above the retina’s sensitivity threshold and larger than the retina’s resolving power
Seeing (entity-seeing)
Subject S sees concrete entity x iff S registers x and S is aware of x
Observe concrete entity
S observes concrete entity x iff S registers x, S is aware of x and S pays close attention to x
(observe = looks at = watches)
conceptual seeing
subject S sees that F(x) iff S registers x, S is aware of x, S possesses the language of which F is a predicate, and forms the observational belief that F(x)
T-infected
Theory-ladenness, observational beliefs and judgements are T-infected
What is it that we observe and see
- phenomenologically we see indirectly: we are conscious of images on the retinas of our eyes, and we are aware of sensations caused by present entities, thus we see entities indirectly (metaphysical anti-realism)
- realistically we see directly: we observe present entities directly, as they are
Threefold role of observation
- observation as a source of knowledge (context of discovery & pursuit)
- observation as a means of testing hypotheses, models & theories (context of justification)
- observation as a mean to refine, adjust & develop h, m & t’s (context of pursuit)
observational predicate
A predicate in a language, say F, is observational iff given any specific observable entity, say a, every human being under normal circumstances can (learn to) judge on the spot whether F(a) is true or false by performing only an observation, thus without making any inferences.
Observational predicates express observational concepts.
F is observational if -F is observational.
Normal circumstances for observational predicates
- psychologically normal (not under influence of alcohol, drugs that impair cognitive capacities)
- biologically normal (not be blind)
- physically normal (S can survive and the entity can persist)
Theoretical concepts
concepts that occur in some theory and are neither logical, mathematical or observational.
T-theoretical concepts: concepts that occur in theory T
(for example: temperature, mass, state, force, species, gene, molecule, atom, chemical reaction, tectonic plate)
observational predicates - observable concrete entities
the entity to which any putative observational concept can be applied meaningfully needs to be observable to human beings: observational predicates only have observable concrete entities in their meaning-conditions
Abstract entities cannot be observed and are more-or-less unobservable by conception. Meaningless.
Observability
Concrete entity x is observable iff for every human being S under normal circumstances: if S were in front of x in broad daylight with eyes wide open long enough, then S would see x.
Observability = anthropocentral –> observability to human beings
proof
deductive argument, provides epistemic justification, provided the premises of the argument are known
evidence
weaker kind of justification for a proposition than proof, but still quite strong: the kind of justification that science requires for its propositions in order to promote knowledge-claims to the desired epistemic status of knowledge.
logically simple sentence
a sentence is logically simple iff the sentence does not contain variables, quantors, or junctors or modal operators.
Logically simple sentences only contain primitive predicates and names (closed atomic sentences).
Always consistent: never imply a single contradiction
actual sentence
sentence is actual iff it is only about concrete entities that exist
Analytic/ conceptual sentence
Sentence is analytic or conceptional iff it is true or false by virtue of the meaning of (the words in) the sentence
Synthethic if not analytic.
Observational sentence
sentence is observational iff it is synthetic, logically simple, contains only observational predicates, is only about observable entities, or is a consistent junctorial combination of these
empirical evidence sentence
sentence is empirical evidence iff it is observational, actual and true.
A sentence is possible empirical evidence iff it is observational and actual
theory-infectedness of scientific observation
‘observation language’ of science is a philosophical construction at best and a philosophical illusion at worst.
Scientific observation reports contain scientific evidence that often involves theoretical concepts or sentences presuppose some kind of theory
five threats of theory-infected observation reports
- anti-positivist threat
- anti-test threat
- blinders threat
- expectation bias threat
- circularity threat
anti-positivist threat
reducing all scientific knowledge to sense experiences, collapses as soon as observation sentences cannot be delineated and such reports are infected by theory
anti-test threat
when scientific observation reports are infected by theory, will such evidence not always confirm theory T? is information of T still possible?
blinders threat
when scientific observation reports are infected by theory T, do these T-concepts not make one blind to anything that cannot be expressed by means of them?
expectation bias threat
when submerged in theory T, and its concepts, we expect unconsciously to see, observe & measure what T tells us what we should see, observe and measure.
semantical blinders threat
we can only say and write what is expressible in languages that we master, which makes it difficult to see things that cannot be expressed within a conceptual framework that we are submerged in.
saliency blinders threat
When we inquire empirically into some phenomena by mere observation or experimentation, we are guided by what we have in mind, usually some theory or model. Observation always has a purpose. what is salient (noticeable) is defined by the theory we already have in mind.
Circularity threat
to justify the truth of theories by means of observations and measurements (confirmation), one needs empirical biconditionals, in order to justify empirical biconditionals, one needs true theories.
Alleviating the Circularity threat
- which part of theories need empirical biconditionals? when these neither include nor imply the hypothesis in question, then the hypothesis is independent from what is presupposed.
- empirical biconditionals which are analytic truths (no need for observational evidence to justify them)
- empirical basis of Popper: empirical basis sentences are motivated by observations, decided on a case-by-case basis by consensus or unanimity within experts in a relevant discipline.
