Unlike experienced witnesses such as police officers, they will anticipate with some dread entering an unknown and possibly hostile arena.
The situation will be particularly extreme for those who are "complainers" – that is to say the alleged victims of the crime.
Can anything be done to help these folk, who after all have done nothing wrong?
After all they are assisting the justice process by going into the witness box to give evidence about what may well have been a very traumatic incident. Scots law is clear on this.
Nobody is permitted, not even the lawyers involved in the upcoming criminal proceedings, to prepare witnesses by rehearsing their evidence.
An example would be going through the questions which are expected to be put in order to ascertain the most convincing answers which the witness might give.
A mock court session might be constructed including questioning, but doing this amounts to the crime of attempting to pervert the course of justice.
In our courts, conviction on this charge almost always results in a jail sentence. Any lawyer participating in such a process would be guilty of professional misconduct and liable to be disciplined by the relevant professional body.
Experienced criminal lawyers will not not be unsympathetic to the fear felt by witnesses before they are called to take the oath.
But the greater harm would undoubtedly be to allow what in effect amounts to the coaching of witnesses. That would be an attack on the very fabric of the justice system.
It is fundamental to the integrity of our Scots system that this is prohibited.
Although these rules are most likely to be relevant in criminal matters, they apply with equal force to civil cases.
There is no reason to think that they don't also apply to evidence to the Scottish Parliament, particularly when that evidence is given under oath.
So it is shocking to see that the answer to a Freedom of Information request to the Scottish Government reveals that the civil service witnesses who were to give evidence to the Salmond inquiry committee had received over £54,000 worth of "external preparation" for their appearances.
What was going on here?
It would have been permissible for the in-house lawyers employed by the Scottish Government to explain to the civil servants just how the committee appearance might work. But they certainly couldn't "prepare" these witnesses, by discussing their evidence, without committing a crime.
There are about 140 lawyers employed by the Scottish Government. It is impossible to believe that none have any knowledge of the procedure of government committees.
Why then was any external help needed? Why did it cost over £54,000?
We know that the external advice came from lawyers because the Scottish Government's FOI answer admits this.
It advances the fact that the advice was legal advice as a basis for refusing to disclose any details about it other than the cost.
This, of itself, is extraordinary, but the Scottish Government's FOI answer also talks of "its work on civil servants evidence" (to the committee).
What work? How can you "work on evidence" without breaking the law?
When we look at the very high number of hours the individual witnesses estimate as the time expended on preparation, it becomes pretty much impossible to conclude that this legal advice was of the very limited type which is permissible.
There is something distasteful about all this.
Our Scottish system does not afford this facility of "preparation" to witnesses who have been the victims of serious sexual assault.
Is a woman who has been raped not more deserving of supportive attention than civil servants who are simply explaining their work to a committee?
That raped women will find her assistance restricted to support from the police, Rape Crisis Scotland or Victim Support Scotland.
All theses bodies are well aware of the restrictions on their discussing the content of evidence with rape complainers. The Scottish Government it seems are not.
Examination of the history here inexorably leads to the view that despite the criminality of so doing, the civil servant witnesses were indeed prepared by rehearsing their evidence. Only that explanation appears to fit in with the facts and the costs.
It would be useful to know if those civil service witnesses who were recalled to the committee were advised by the mysterious "external advisers" between their appearances.
For example, the head of the civil service was called to give evidence no fewer than four times because her answers raised questions requiring further inquiry.
The document attached to the FOI answer by the details given of dates indicates that there was such preparation between committee sessions.
There was also discussion between some witnesses regarding the questioning which had already occurred and that which was likely to occur. Both are completely improper.
It appears a serious crime has taken place.
Both the inquiry hearings and the Freedom of Information answer given by the Scottish Government are in the public domain.
So the Procurator Fiscal's office and Police Scotland are well aware of all the facts set out above. There must now be a police investigation.
The result of that investigation could well be prosecutions. Any attempt to undermine justice itself must always be resisted.
- Alistair Bonnington is a former honorary professor at Glasgow University School of Law.