This is a proceeding in mandamus. We take the facts from the alternative writ and supporting documents. Plaintiff is the defendant in an underlying criminal prosecution. (Hereafter he is referred to as “defendant.”) He entered a no contest plea to a felony charge of sexual abuse in the first degree. Apparently a presentence investigation was ordered to be performed by the Multnomah County Diagnostic Center. That agency requested the defendant to appear for interviews, including a psychological interview, but refused as a matter of practice to permit the defendant’s attorney to attend the interviews. Defendant then moved to allow his attorney to attend the interviews. The motion was denied by the circuit judge, the successor of whom is defendant in this proceeding. The court stated its reasoning:
“I recall very well, Mr. Baron [defense counsel], that I accepted the plea of no contest with reluctance, and only after the importuning of yourself regarding the unique circumstances of this crime and your client’s attitude towards the criminal justice system. The thrust of your argument is not so much to urge the necessity of legal counsel as a legal advisor but that this man needs someone with whom he trusts and would feel more comfortable and ask that you be there. You have not made any argument, at least convincing me, that your legal services are necessary.”
The trial court concluded that because there was no need for legal services, due process did not require the presence of counsel. The writ would require that the order of denial be vacated and that the trial court allow defense counsel to be present at presentence interviews.
Defendant asserts three constitutional bases for a right to the presence of his attorney at the presentence investigation interviews. His first contention is under the right to counsel provisions of Article I, section 11, of the Oregon Constitution, and the Sixth Amendment to the United States Constitution. Second, he asserts a right to the presence of counsel as ancillary to his right not to be compelled to testify against himself in any criminal prosecution, rights guaranteed under Article I, section 12, of the Oregon Constitution, and under the Fifth Amendment to *315the United States Constitution. His third contention is that, under the circumstances of this case, “fundamental fairness,” as embodied by the Due Process Clause of the Fourteenth Amendment, mandates the presence of his attorney to insure his right to a fair trial. Finally, the defendant contends that the trial court abused its discretion in denying the defendant’s motion to have counsel present at the presentence interview. We issued the alternative writ of mandamus to consider whether criminal defendants have a right to have counsel attend the presentence interviews.
Article I, section 11, states that the accused shall have the right “to be heard by himself and counsel” in “all criminal prosecutions.” The term “criminal prosecution” includes sentencing, a stage at which a judicial decision affecting a defendant’s future liberty is made. Obviously, then, a defendant is entitled “to be heard by himself and counsel” at sentencing. A short answer, therefore, is that counsel cannot be excluded from any stage of the criminal prosecution at which a defendant is to be “heard,” including the sentencing stage, whether this is wholly performed by the judge or shared with non-judicial persons.
Beyond this short answer, we have the benefit of decisions of the United States Supreme Court under the Sixth Amendment, which, as is demonstrated by the excellent historical review in the dissent, was intended to assure similar protection to that stated in Article I, section 11. Under those decision, insofar as they affect this case, a criminal defendant’s guarantee of the assistance of counsel exists at least at all court proceedings from arraignment through probation revocation as well as all post-indictment out-of-court critical stages where, without the assistance of counsel, the legal interests of the defendant might be prejudiced. Specifically, sentencing is a critical stage of a criminal prosecution at which a defendant is guaranteed counsel. Mempa v. Rhay, 389 US 128, 88 S Ct 254, 19 L Ed 2d 336 (1967); Gebhart v. Gladden, 243 Or 145, 412 P2d 29 (1966). We agree with the dissenters as to the nature of those principles, but our application of them differs from that of the dissent because of our different view of the nature of a presentence investigation, to which we now turn.
*316Before pronouncing sentence, a trial court will wish to be informed of such relevant information as the circumstances of the offense and the criminal record, social history and present condition and environment of the defendant. Before presentence reports were common, this information was generally provided at the sentencing hearing by the prosecutor, the defendant, defense counsel and other sources. Today, ORS 137.530 provides an alternative method of gathering such information. Instead of the court doing so directly, it may direct probation officers to perform the initial task on behalf of the court, and to report back to the court:
“Probation officers, when directed by the court, shall fully investigate and report to the court in writing on the circumstances of the offense, criminal record, social history and present condition and environment of any defendant; and unless the court directs otherwise in individual cases, no defendant shall be placed on probation until the report of such investigation has been presented to and considered by the court. Whenever desirable, and facilities exist therefor, such investigation shall include physical and mental examinations of such defendants.” ORS 137.530.
The court may also designate a person other than a probation officer to conduct the investigation. ORS 137.090.
Defendant alleges that the presentence investigator, the diagnostic center, “told [him] to report for a psychological interview” as well as for a “general interview.” Defendant does not dispute that the authority of the court to designate one other than a probation officer to make a presentence investigation, ORS 137.090, includes authority to designate the diagnostic center and that an interviewer may be a psychologist as well as anyone else.
A judge’s election to gather sentencing information through the agency of a probation officer or another makes the process no less a judicial procedure than when the judge does so directly. The investigation is simply an out-of-court inquiry and hearing on behalf of the judge. When the information has been gathered for the judge, the information in the report may be challenged and supplemented at the sentencing hearing. The information in the presentence report, other than certain diagnostic or confidential *317reports, may be disclosed to the state and the defendant, ORS 137.079, see also, Buchea v. Sullivan, 262 Or 222, 497 P2d 1169 (1972), and either party may complete the fact-gathering by offering evidence in aggravation or mitigation, ORS 137.080-137.100.1 In other words, the investigator informally performs for the judge a function, in part, which would otherwise be performed by the judge as part of the formal sentencing hearing. Functionally, the investigation is a part of the sentencing procedure.
A defendant is entitled to the assistance of counsel to the same degree when the judge seeks sentencing information from him in open court and when the judge does so indirectly through the out-of-court agency of a probation officer. Therefore we conclude that just as a sentencing hearing to determine a defendant’s future liberty is a stage of a prosecution at which the assistance of counsel cannot be denied, so is a presentence interview. The order barring counsel was unauthorized.
We do not suggest that every defense attorney is duty bound to accompany his or her client at the probation office. Often, little purpose would be served by the presence of counsel at a presentence interview and a conscientious *318defense attorney would not necessarily feel obliged to attend to protect his client’s interests. After guilt is no longer in issue, the inquiry is into defendant’s background, present situation and attitude. At the hearing, the report of information given by the defendant is subject to disclosure and defense counsel can make objections and present evidence and additional statements by defendant. Given these procedural opportunities, rarely would there be risk of irremediable harm from the absence of counsel at the presentence interview. Yet, circumstances are conceivable where the presence of counsel would be helpful. We do not hold that the presence of counsel is required at every presentence interview or that his absence would constitute ineffective assistance of counsel. Rather, we hold only that Article I, section 11, and the Sixth Amendment require that counsel may not be barred from attendance at a presentence interview.
Defendant’s contentions under the self-incrimination provisions of Article I, section 12, and the Fifth Amendment, if material at all, are premature. Other than ORS 137.100, discussed below, we find no legal authority for a judge or probation officer to compel an unwilling defendant to make statements in the course of the sentencing process, whether in or out of court. Nor may he be compelled to submit to psychological interviews. No issue of compelled self-incrimination arises because there is no statutory or other authority to compel defendant to provide any information, regardless of whether it is incriminatory.2
If a defendant offers himself or is called as a witness in mitigation or aggravation pursuant to ORS 137.100, see n 1, he would then be subject to compulsion to testify generally and a question of compelled self-incrimination might arise. At that time some issue of the post-conviction scope of the privilege would be presented, but this case presents no such issue.
The decisive factor in any presentence setting is' not the official capacity or profession of the presentence *319investigator or the setting in which the inquiry is made, but rather the willingness of the defendant to provide information. A defendant with counsel may be expected to know that a purpose of a presentence investigation is to assist the court in determining whether a convicted defendant is more likely to respond to probation or incarceration and to what extent. State v. Scott, 237 Or 390, 399-400, 390 P2d 328 (1968). Indeed, ORS 137.530, although it allows exceptions, directs that “no defendant shall be placed on probation” until a presentence report is considered. Thus, the decision whether to cooperate by providing the court with desired information is likely to be motivated by knowledge of the practical consequences: if one wishes leniency, he is likely to cooperate in the presentence investigation. If a defendant declines to cooperate, or if his attorney injects himself in a way which reduces the effectiveness of the inquiry or examination, then the defendant subjects himself to sentencing based on less complete information and the direction of ORS 137.530 becomes applicable. With the assistance of counsel, a defendant can decide advisedly and voluntarily whether it is in his best interests to submit to interviews and examinations and, if so, whether with or without his attorney in attendance.
In this case, for example, if defendant declines to cooperate or if the defendant’s attorney attends and his service interferes with the ability of the psychologist to conduct an effective, complete psychological examination, then the judge may be required to impose sentence upon a noncooperative defendant based on the other information before the court which, according to the petition, is:
“Plaintiff-Relator entered his plea of no contest because of psychological factors: the circumstances of this case involve sexual contact with two young girls, and an evaluation by a court-appointed psychologist — Dr. Howard Dewey — disclosed that it would be too psychologically traumatic for plaintiff-relator to have to plead guilty or face trial. Dr. Dewey considered and noted that plaintiff-relator had twice before been diagnosed by Dammasch State Hospital as suffering from schizophrenia — paranoid type.”
In such cases as this, defendants and defense counsel are not likely to find it in their self-interest to impede the *320process. Were that counsel’s intention, he would more discreetly advise his client not to submit to examination at all. For these reasons, we expect the practical effects of our holding to be negligible in most cases, but helpful to the fact-gathering process or to the protection of the clients’ rights in the exceptional cases where defense attorneys deem it advisable to attend presentence investigations or to witness psychological examinations.
It is hard to anticipate why a defense attorney would wish to attend a presentence interview or examination or what professional service he could perform if present. Cf., United States v. Wade, 388 US 218, 87 S Ct 1926, 18 L Ed 2d 1149 (1967). Here, consistent with the trial judge’s observations, the petition alleges a need for the attorney to provide what is essentially moral support rather than legal service. Nevertheless, we hold that counsel cannot be barred and the trial court had no authority to do so.
Peremptory writ issued.
ORS 137.080:
“After a plea or verdict of guilty, or after a verdict against the defendant on a plea of former conviction or acquittal, in a case where a discretion is conferred upon the court as to the extent of the punishment to be inflicted, the court, upon the suggestion of either party that there are circumstances which may be properly considered in aggravation or mitigation of the punishment, may, in its discretion, hear the same summarily at a specified time and upon such notice to the adverse party as it may direct.”
ORS 137.090:
“The circumstances which are alleged to justify aggravation or mitigation of the punishment shall be presented by the testimony of witnesses examined in open court, except that when a witness is so sick or infirm as to be unable to attend, his deposition may be taken out of court at such time and place, and upon such notice to the adverse party, and before such person authorized to take depositions, as the court directs. The court may consider the report of presentence investigation conducted by probation officers pursuant to ORS 137.530 or any other person designated by the court.”
ORS 137.100:
“If the defendant consents thereto, he may be examined as a witness in relation to the circumstances which are alleged to justify aggravation or mitigation of the punishment; but if he gives his testimony at his own request, then he must submit to be examined generally by the adverse party.”
A presentence investigation differs in this respect from a compulsory psychiatric examination under ORS 161.315 for evidence of mental disease or defect. Shepard v. Bowe, 250 Or 288, 442 P2d 238 (1968), and its progeny have no application to this case.