Considerable effort needs to be invested in the initial programme theory, but it should not be regarded as fixed and immutable; it may develop over time as those engaged in the programme learn from their experiences of implementation.
"People change over time.
Our memories are not immutable; they evolve over time.
Researchers, including social scientists, state that often behavior and identity do not match: women may label themselves heterosexual but have sexual relations with women, self-identified lesbians may have sex with men, or women may find that what they considered an immutable sexual identity has changed over time.
To those of you who haven't read about the 10th Immutable Law in my book The 22 Immutable Laws of Marketing, it goes like this: Over time, a category will divide and become two or more categories.
Does the meaning of the Constitution evolve over time, or is there only a single, immutable understanding of what it says?
Since a subject's values can be expected to change over time, what is required is not an immutable, fixed, set of values, but a minimally consistent and stable set of values (Buchanan & Brock 1989, 24).
In addition, both the ATBC study and the PLCO study were based on one measurement of 25(OH D in blood, which most likely reflects recent exposure to sources of vitamin D rather than long-term average vitamin D level; whereas the 25(OH D prediction score would track well over time because factors that influence the score, such as race and residential region, are immutable or relatively stable.
Firstly, genomic data are immutable; other than a relatively small number of somatic mutations, an individual's DNA sequence does not markedly change over time.
